I've had the same problem with the trackball icon freezing on the screen as many others have via other forums.  I've also had the phone freeze up for about 5 seconds - pressing any button will not do anything  - then it suddenly starts working.  My reboot time has gone from about 4 minutes to almost 10.  Some have had reduced reboots by removing Google Maps - others have no problems with it. The back of the phone gets pretty hot (below battery) when used for more than 5 minutes - possibly the main processor?  There also seems to be more problems with phones built south of the border than north of it.  Any one else on here having these problems/issues?      And yes, I've adjusted my trackball sensitivity several times - I think it may be more of an OS issue.