Either you've got a wirm or enabled some bizarre cursor tracking option by accidentally hitting a hot key. In either case System Restore might help. If you don't mind using it that is.
Also, a simple thing like mouse/scroller speed set to higher values can cause the cursor to jump around the screen each time new windows open. But looks it you've played with that stuf already.
Personally I get that annoying "jumping cursor" a lot. But I'm forced to use screen reader/magnification applications and they are notorious for bugs related to screen redraw and cursor tracking.
-ED-