My problem is that in Firefox (not IE6, 7, 8 or Opera; surprisingly) on a CSS-styled 3-deep unordered list, Firefox loses focus when going to the third element. That may sound ambiguous; let me elaborate. Say the first element of Programs, the second is GPEP, and the third is a list of 5 different things. When I hover on GPEP, the third menu displays, with the first element called Overview, level with GPEP. When I move my mouse down to the next item in the third list, which is called Program Components, GPEP loses focus and shifts down to the second item in the second-level of the menu; thus disallowing me from clicking on anything within the GPEP menu except the first element. CSS: #nav { width: 220px; margin: 0; padding: 0px 0 0 0; float: left; margin-right: 20px; } #nav ul { list-style: none; margin: 0; padding: 0; height: 1%; } #nav ul li { line-height: normal; z-index: 100; } #nav li { margin: 0; } #nav .navHeader { padding: 0; margin: 0; font-size: 2.0em; } #nav .navHeader a{ color: #fff; font-size: 0.65em; font-weight: normal; display: block; padding: 4px 5px 4px 20px; background-color: #006633; border-bottom: solid 1px #695e4a; margin: 0; } #nav .navHeader a.active { background-color: #4b3242; } #nav .navHeader a.open { background-color: #ffffff; border-bottom: 1px solid #4b3242; color: #4b3242; } #nav a { text-decoration: none; font-size: 100%; } #nav h2 a { color: #ffffff; } #nav a:hover { text-decoration: underline; } #nav li { position: relative; } #nav ul li { background-color: #fff; color: #000; margin: 0; padding: 0; text-align: left; } #nav li.navEnd{ margin-bottom: 0.3em; } #nav ul ul li a { color: #000; display: block; padding:3px 3px 0px 40px; font-weight: normal; border-bottom: solid 1px #695e4a; } #nav ul ul ul li a { color: #fff; background: #006633; display: block; padding:3px 3px 3px 40px; font-weight: normal; border-bottom: solid 1px #695e4a; } #nav ul ul li a.active { background-color: #4b3242; color: #ffffff; } #nav ul ul ul li a.active { background-color: #4b3242; color: #ffffff; } #nav ul ul.hide { position: absolute; top: 0; left: 100%; z-index:500; background-color: #006633; width: 13em; } #nav ul ul ul.hide { position: absolute; top: 0; left: 100%; z-index:500; background-color: #006633; width: 13em; } #nav ul ul.hide li a { padding: 3px 3px 3px 5px; } #nav ul ul ul.hide li a { padding: 3px 3px 3px 5px; } #nav ul ul { display: none; } #nav ul ul ul { display: none; } #nav ul ul ul li { display: none; } #nav ul li:hover ul { display:block; } #nav ul ul li:hover ul li{ display:block; } #nav ul ul li { width: 100%; } #nav ul ul ul li { width: 100%; } #nav ul ul li a{ height: 1%; } #nav ul ul ul li a{ height: 1%; } #nav ul ul.show { display: block; } #nav ul ul ul.show { display: block; Code (markup): HTML: <div id="nav"> <ul> <li><span class='navHeader'><a href='/about/index.php' title='About' >About</a></span> <ul class='hide'> <li><a href='/about/index.php' title='Goto Scholarships and Awards' >Mission</a></li> <li><a href='/about/overview.php' title='Goto Scholarships and Awards' >Overview</a></li> <li><a href='/about/goals.php' title='Goto Scholarships and Awards' >Goals</a></li> <li><a href='/about/directorsmessage.php' title='Director′s Message' >Director′s Message</a></li> </ul> </li> <li><span class='navHeader'><a href='/programs/index.php' title='Programs' >Programs</a></span> <ul class='hide'> <li><span class=''><a href='/programs/gpep_overview.php' title='GPEP' >GPEP</a></span> <ul class='hide'> <li><a href='/programs/gpep_overview.php' title='Overview' >Overview</a></li> <li><a href='/programs/gpep_programcomponents.php' title='Program Components' >Program Components</a></li> <li><a href='/programs/gpep_requirements.php' title='Requirements' >Requirements</a></li> <li><a href='/programs/gpep_admission.php' title='Admission' >Admission</a></li> </ul> </li> <li><span class=''><a href='/programs/sgpep_overview.php' title='SGPEP' >SGPEP</a></span> <ul class='hide'> <li><a href='/programs/sgpep_overview.php' title='Overview' >Overview</a></li> <li><a href='/programs/sgpep_programcomponents.php' title='Program Components' >Program Components</a></li> <li><a href='/programs/sgpep_admission.php' title='Admission' >Admission</a></li> </ul> </li> <li><span class=''><a href='/programs/gsep_overview.php' title='GSEP' >GSEP</a></span> <ul class='hide'> <li><a href='/programs/gsep_overview.php' title='Overview' >Overview</a></li> <li><a href='/programs/gsep_programcomponents.php' title='Program Components' >Program Components</a></li> <li><a href='/programs/gsep_requirements.php' title='Requirements' >Requirements</a></li> <li><a href='/programs/gsep_admission.php' title='Admission' >Admission</a></li> </ul> </li> <li><span class=''><a href='/programs/gew_overview.php' title='GEW' >GEW</a></span> <ul class='hide'> <li><a href='/programs/gew_overview.php' title='Overview' >Overview</a></li> <li><a href='/programs/gew_workingconditions.php' title='Working Conditions' >Working Conditions</a></li> </ul> </li> <li><span class=''><a href='/programs/gaap_overview.php' title='GAAP' >GAAP</a></span> <ul class='hide'> <li><a href='/programs/gaap_overview.php' title='Overview' >Overview</a></li> <li><a href='/programs/gaap_preparation.php' title='Preparation' >Preparation</a></li> <li><a href='/programs/gaap_applyonline.php' title='Apply Online' >Apply Online</a></li> <li><a href='/programs/gaap_senddocuments.php' title='Send Documents' >Send Documents</a></li> <li><a href='/programs/gaap_reviewadmission.php' title='Review Admission' >Review Admission</a></li> <li><a href='/programs/gaap_beforeyouleave.php' title='Before You Leave' >Before You Leave</a></li> </ul> </li> </ul> </li> <li><span class='navHeader'><a href='/admissions/index.php' title='Admissions' >Admissions</a></span> <ul class='hide'> <li><span class=''><a href='/admissions/gpepsgpep_overview.php' title='GPEP/SGPEP' >GPEP/SGPEP</a></span> <ul class='hide'> <li><a href='/admissions/gpepsgpep_overview.php' title='Overview' >Overview</a></li> <li><a href='/admissions/gpepsgpep_preparation.php' title='Preparation' >Preparation</a></li> <li><a href='/admissions/gpepsgpep_applyonline.php' title='Apply Online' >Apply Online</a></li> <li><a href='/admissions/gpepsgpep_senddocuments.php' title='Send Documents' >Send Documents</a></li> <li><a href='/admissions/gpepsgpep_reviewadmission.php' title='Review Admission' >Review Admission</a></li> <li><a href='/admissions/gpepsgpep_beforeyouleave.php' title='Before You Leave' >Before You Leave</a></li> </ul> </li> <li><span class=''><a href='/admissions/gsep_overview.php' title='GSEP' >GSEP</a></span> <ul class='hide'> <li><a href='/admissions/gsep_overview.php' title='Overview' >Overview</a></li> <li><a href='/admissions/gsep_preparation.php' title='Preparation' >Preparation</a></li> <li><a href='/admissions/gsep_applyonline.php' title='Apply Online' >Apply Online</a></li> <li><a href='/admissions/gsep_senddocuments.php' title='Send Documents' >Send Documents</a></li> <li><a href='/admissions/gsep_reviewadmission.php' title='Review Admission' >Review Admission</a></li> <li><a href='/admissions/gsep_beforeyouleave.php' title='Before You Leave' >Before You Leave</a></li> </ul> </li> <li><span class=''><a href='/admissions/gaap_overview.php' title='GAAP' >GAAP</a></span> <ul class='hide'> <li><a href='/admissions/gaap_overview.php' title='Overview' >Overview</a></li> <li><a href='/admissions/gaap_preparation.php' title='Preparation' >Preparation</a></li> <li><a href='/admissions/gaap_applyonline.php' title='Apply Online' >Apply Online</a></li> <li><a href='/admissions/gaap_senddocuments.php' title='Send Documents' >Send Documents</a></li> <li><a href='/admissions/gaap_reviewadmission.php' title='Review Admission' >Review Admission</a></li> <li><a href='/admissions/gaap_beforeyouleave.php' title='Before You Leave' >Before You Leave</a></li> </ul> </li> </ul> </li> <li><span class='navHeader'><a href='/life/index.php' title='Life @ VIPP' >Life @ VIPP</a></span> <ul class='hide'> <li><a href='/life/index.php' title='Summary' >Summary</a></li> <li><a href='/life/informationlinks.php' title='Information and Links' >Information and Links</a></li> </ul> </li> <li><span class='navHeader'><a href='/people/index.php' title='VIPP People' >VIPP People</a></span> <ul class='hide'> <li><a href='/people/index.php' title='VIPP Staff' >VIPP Staff</a></li> <li><a href='/people/advisorycommittee.php' title='Advisory Committee' >Advisory Committee</a></li> <li><a href='/people/gipccinstructors.php' title='GIPCC Instructors' >GIPCC Instructors</a></li> <li><a href='/people/recentparticipants.php' title='Recent Participants' >Recent Participants</a></li> </ul> </li> <li><span class='navHeader'><a href='/news/index.php' title='News & Events' >News & Events</a></span> <ul class='hide'> <li><a href='/news/index.php' title='Latest News' >Latest News</a></li> <li><a href='/news/upcomingevents.php' title='Upcoming Events' >Upcoming Events</a></li> <li><a href='/news/globalearchive.php' title='Global-E Archive' >Global-E Archive</a></li> <li><a href='/news/speakerseries.php' title='Speaker Series' >Speaker Series</a></li> <li><a href='/news/vippcalendar.php' title='VIPP Calendar' >VIPP Calendar</a></li> </ul> </li> </ul> </div> Code (markup): Any help would be greatly appreciated. I've tried quite a few things and still can't figure it out. I'm used to fixing things in IE; not Firefox.