I have previously reported sluggish mouse on Vista. The symptoms were 3-5x slower mouse cursor movement on screen. Another symptom was high CPU usage of wdm.exe, Windows Display Manager.
Today, the same problem occurred. Sluggish mouse. Mouse by the way is the Microsoft model 3000 about three years old. Really works well, you can see it here: http://mouseforlaptop.org. That is, it works well when it is not sluggish.
The main symptom today was the same - sluggish mouse cursor. However, inspecting Windows Task Manager, the dwm.exe was not using extraordinary amounts of cpu time, and neither was any other process. Also, the computer did not come out of hibernate. The sluggish mouse appearance DID coincide with a large download (11000 items) of email from an IMAP server.
However, the latest solution, http://annoyances-resolved.blogspot.com/2009/11/sluggish-pointer-on-windows-vista-and.html
worked this time as well. All I needed to do is bring the laptop back to sleep (not hibernate) and bring it back up. Mouse sluggish no more!
If you had similar experiences, please let me know in your comments below!