Login "stuck" for certain user

[manipulator]

We have 200+ email user, but this problem happen to few user at a time only.
Problem can be resolve by restarting Mailbox service or zmcontrol. But restarting the service will cause interruption to all users. Is there a way to reset the particular user only and why is this happened.

When user login, it will stuck at login loading screen in "ajax" mode, and if switched to HTML mode, it come out weird weird interface. Refer to attached picture.

Please help and advice. Thank you.

[Meowmixjinx]

my users occasionally have similar problems when using IE to view zimbra(5.0.x) and the page caches incorrectly. I usually have to clear IE's cache before and then everything is fine. Again not the best solution but it doesn't require restarting the server.

[manipulator]

my users occasionally have similar problems when using IE to view zimbra(5.0.x) and the page caches incorrectly. I usually have to clear IE's cache before and then everything is fine. Again not the best solution but it doesn't require restarting the server.

Yes, IE occasionally give us ajax problem, so now we are using FireFox only. But our issue is not same as yours, for example, I got no problem loading my email account in my computer with FireFox, but I can't load other persons account that reported got "hang" issue, so I'm sure the issue is not because of computer caches.