Mighty mouse anything but

I've been using a Mighty Mouse for 4 months and all of a sudden the track ball will only scroll left, right and down. Scrolling up no longer works.

Anybody else come across this? Apple mice always seem to go faulty neye:

Sorry, found an old thread about it. Can someone delete this?

I know you may have it solved, but for anyone who doesnt, this works a great:

http://docs.info.apple.com/article.html?artnum=302417

I had 2 mighty mouses doing the same as yours, and it was driving me crazy. Now both working and have recently brought a wireless one.