Also have swipe problems
I got the Magic mouse close to when it came out and it was working fine. I downloaded the new OS update, 10.6.2 and then noticed, that no matter what I did, I couldn't get the swipe to work. Went to level 2 support and they asked me to bring the mouse back to the retail store so Apple Tech support (level 2 people at Apple) could study it. They replaced my mouse at the apple store but a week later, after a sudden power loss on the apple (for no apparent reason), and restarting, I'm encountering the same problem. I guess I'll have to replace this one as well. The scrolling still works but the swipe doesn't. Very strange.
I hope Apple fixes this soon. I saw some fixes on apples site but sounds like it needs to be done every time I reboot. A bit of too much effort for me to do it everytime. BTW, I'm using a 24 inch iMac 3.06 GHz 4GB , 1 TB HD w/HD4850 ATI Video (last hardware update before the new iMac 27in)