I have seen this problem on 3 different computers recently, in each case it was a brand new intel system with new components (motherboard etc) with the exception of the keyboard and mouse, and the only OS used was Win 7 64 bit. In every case the mouse was a USB basic microsoft optical mouse, the system recognised the mouse without any stated errors but the mouse pointer would be frozen on the desktop.
In every case the mouse was purchased around 12 months ago and was stated on it's packaging to be compatabile with OS up to and including Vista, when a new basic Microsoft optical mouse (latest version compatible with Win 7) was substituted the problems disapppeared and have not occurred since, there were no driver updates or other software changes applied.
The mice on all 3 systems were replaced with current MS versions compatible with Win 7 and the systems have functioned without any problems since, all the older mice replaced are currently being used on other systems with XP and Vista also without any problems.
When using the new and old mice on an XP system, the only difference I can detect is that the new mice are very slightly more responsive, as I didn't have the time to investigate further, I can only assume there is the possibility of a compatibility problem
I ran into a few strange problems with my "old" Microsoft optical mouse when I built a brand new system and installed Windows 7 Pro 64 bit. Replacing the mouse with a new model solved the problem. Works fine now. What I don't know is what caused the intermittent problems.