I got the dredded "This Account Has Exceeded Its CPU Quota" from hostmonster today. I've noticed the two sites they host for me have slowed down quite a bit this last week. one of the sites is a vbulletin forum that gets 15-20 users on at a time at most. A call to tech support resolved nothing. His answer was, Vbulletin software is generally cpu intensive, you may want to upgrade to a faster cpu server. The 8 CPU server had a load of 17% today at one point. I have no external modified java script mods running on my site now. ???
My HostMonster account has been slow as molasses for a month or two now. It has gotten progressively worse. I have since purchased a virtual dedicated server at Media Temple and moved 15+ sites. I have one more site to move but have been having trouble with the MySQL database being compatible. It will probably be fixed soon. Then good riddance to HostMonster. HostMonster was great when I got there about a year ago but perhaps my sites have outgrown it. I also think they are cutting corners by (1) putting more sites on less resources, (2) lowering customer service quality and (3) generally trying to cut expenses with no regard for the customer's experience. After all, your downtime and the slow load for your readers does not factor on their income statement.
All shared hosting have a limitation. All boasts of unlimited sites, unlimites MySql, unlimited bandwidth but no one says unlimited resources like CPU usage, Memory usage. If your sites are more then it's better to move to VPS.
What do you expect from a site that advertises unlimited space/bandwidth? I have yet to come across a hard drive that hold's unlimited TB's of data.. if you do, let me know, I'd like to pick one up.