sounds like its not tracking properly on the screen.
Try these:
1) try the mouse on a dark coloured surface like a book, avoid white or clear surfaces.
2) try another USB/SERIAL port
3) Remove any drivers from any previous mice on the pc.
4) get latest drivers from the manufacturer
5) try the mouse on another pc. If the problem follows the mouse, replace the mouse. If the problem aint there on the 2nd pc, theres still a driver from an old mouse on the first pc, or theres an incompatibility issue with another driver.
let me know. rgds.
trixy
http://www.trixysvinyl.com