I have tried IE6 and IE7, it's very intermittent for me. Sometimes i can login and click around for a while and other times i get an alert that pops up with an error. I do not have any issues using Firefox however.
I am not sure that this matters, but i have compiled my own version of PHP since i need 5.1+ for some apps, but i have followed the same procedure as the version 2 series without issue.
System info is as follows:
Server: LiteSpeed/3.0.2 Standard
OS: Ubuntu Edgy Linux
Version: #3 SMP Sun Oct 15 13:15:34 BST 2006