I was having trouble with an Apple Magic Trackpad. I was using it with Windows 7 on a PC, so I don’t know whether it happens with OS X or in Boot Camp, but I suspect it does.
The symptoms were that the trackpad worked fine for a few minutes, then mouse movement became erratic. The trackpad would develop a dead zone in the middle, and only recognize movement in some directions. The only way to cure it at that point was to remove/replace (plug/unplug) the Bluetooth dongle on the PC. Then it was OK for a few minutes more.
I suspected Bluetooth interference, so I turned off all other Bluetooth devices (laptops, cell phone, headsets, etc.) or so I thought! I forgot about my AT&T 2-line DECT 6.0 phone (TL86109/86109). This desk phone (a.k.a. land line) is willing to talk to Bluetooth headsets, download contacts from cell phones, and use a cell phone as one of the phone lines. (I like it a lot.)
But… I think the trackpad was trying to pair with it. My problems went away when I unplugged the phone power. (One thing I DON’T like about the phone is that you can’t disable Bluetooth.)
I went into the phone’s setup, and changed the pair-authorization code/PIN from 0000 to 9999. The problem APPEARS to be solved. Since it is a sporadic issue, I can’t say for certain yet.
So it looks like the touchpad was pairing with the telephone.