Failed form authentication with IE7

[Sunny]

Hi,
I experience a weird problem with asp.net 1.1 form authentication and IE7.
The application is running on windows server 2000, IIS 5. When I try to
access a page, it redirects me to the login page (as it have to). But after
I enter the login info, it again brings up the login page. It works OK with
Firefox and IE6.

Also, the same application on XP with works just fine.

I'm writing in a log file almost every step of the application, I know that
the login page validates OK the login info. I capture all the events for
the page, and everything works OK till the moment when it have to redirect
to already authenticated internal page.

I have disabled all security settings in IE, allowed all cookies, etc., and
now I'm out of ideas.

Any pointers or clues what I have to check?

Cheers
Sunny