Here: http://support.microsoft.com/kb/934903 you can read about this bug introduced by SP2 (Session_OnEnd in global.asa not being read).

Is there anybody that obtained the hotfx from MS, and wants to generously share it with me?
I spent 20 mins at the phone todaty,giving out my personal info to an operator I could barely understand, to be told that I neded to tell them if it was US or EU software that I was using. I explained I did not know because it comes from my Technet subscription, produced by my company (US) while I am in Italy (EU), and so she wanted me to check on the OS. I had no access to the server in that very moment, so I gave up.

And, I thought maybe the empeg BBS would prove more helpful than any helpdesk, as usual...

However, why on earth MS deced not to make this hotfix available for download, just like the thousand others out there?