MSN logs out when the screen saver comes up :(

This has been happening for months, but I've only just now decided to do something about it. Google didn't really turn up anything, so now I'm asking you all!

Usually what happens is I'll do something else for awhile, then come back and get rid of the screen saver so I can do stuff, and get a little pop up in the corner saying something about Data Execution Prevention and I'm logged out of MSN.

Are you sure its the screen saver and not the auto-sleep? I have this problem too when my computer goes to sleep :(

Only thing you can do is extend the amount of time before your screen-saver comes up I guess.

No, it definitely happens without it falling asleep. However, I'm not entirely sure if it's the screen saver or the display turning off.

If you're on an Acer laptop with Vista:
Acer Support - Frequently Asked Questions list for Windows Live Messenger 8.1 has stopped working after signing in or during use in Windows Vista.

If not:
DEP blockin Live Messenger 8.1
or
Data Execution Prevention in Windows Live Messenger - Super User

Thanks :D!