problems with WM

Hello!

I'm having some problem with my Windows Messenger - it's not displaying
alerts when I receive e-mails anymore.

I already tried everythink.. The plugin is installed, the option is marked
on the WM options, IE default email is redirecting to the hotmail. I even
tried to reinstall WM.

If I click on the "Go to my email inbox" link on WM, it opens my msn account
correctly, but when I receive emails it doesn't pops up an alert..

If someone could help me I would apreciate a lot.. It's really useful to me,
and I just reinstalled XP, I don't want to do that again..

thank you a lot!

Eduardo