Problem doing a button submit, after a windows update (october)

[tete]

Hi there,
i have a website developed with .NET 2.0 that worked very fine until i did
last windows update a week ago.

The problem is that when i click in a button it does not postback and i
can't get authenticated by my website.

If i runs the application at localhost, everything is fine... just doesn't
work with a website hosted in another place and only with ASP.NET 2.0
applications. All others runs just fine.

Appreciate any help.
Thanks in adv.

Fabiano