Here is the page where I used it. http://www.signitas.com/newgen/contact.php working perfactly in FF but showing problem in IE.
First of all, sesson_start has nothing to do with the browser. It's run server side. It either runs or it doesn't. You may have browser specific code but if it gets kicked off in FF then it gets kicked off in ie. Perhaps you are having a cookie issue. Edit: page displays fine in FF and IE for me.
Not sure how it can fil for IE, but if session is cookie based and cookies are not allowed in your IE you can get some troubles.
session_start is a server side function - so it should work even if you telnet to port 80 well, not really, but whatever.
The error was somewhere else in the script not in session_start()and it is solved. Thanks every one for your replies.