This is my second comment on 10.6.1 - the horrible ... I have a M$ bluetooth mouse as well as apple bluetooth keyboard. Both lose connection all the time - of course when the computer goes to sleep - but sometimes even when it doesn't. The bad news are that while in the bluetooth menu for the keyboard there is a "connect" option, for the mice there is only the option "open mouse preferences" where you need to re-pair the mouse in spite of the fact that the mouse was paired previously. I tried to remove the mouse and re-pair it, tried after restart with cntrl-P-R, it just doesnt work. I would love to blame M$ for that, but I know that the mouse worked nicely under 10.5, so its clearly Apple's fault and not M$.