Annoying Alerts

I hope someone can explain this recently I have been getting an annoying alert on my computer that stops anything I am doing and I have to cancel it to continue. It pops up every 10 minutes or so and I need to figure out how to stop it or I'm going to throw my MacBook out the window. It read as follows:

WebDAV File System Authentication
Enter your user name and password to access the server at the URL :http://idisk.mac.com/bdelkei/" in the realm "idisk.mac.com."

No matter what name and password I enter the message continues to appear every 10 minutes.

Anyone?

See if any of this helps. Read especially the 2nd page.

Apple - Support - Discussions - WebDAV File System Authentication? ...

Or try logging into your MobileMe account and add new password there, it may highlight the problem area in that process. Throwing it out the window seems a bit harsh as i am sure there some bods out there who would take it off your hands.