You could try downloading and installing a new version of the mouse
driver, if one is available from the manufacturer's web site. Or, try a
new mouse and driver on the machine.

David McRitchie also has some suggestions on his web site:

http://www.mvps.org/dmcritchie/excel/ghosting.txt


Shane wrote:
I have a user that clicks in a cell on an open excel sheet. She then moves
her mouse and all the cells that she moves the mouse over highlight. It is
almost like she is holding down the left mouse button, but that isn't the
case. I have replaced the mouse, but that did not work. I have checked for
extended being on, but that is not the case either. Any help would be
appreciated.


--
Debra Dalgleish
Excel FAQ, Tips & Book List
http://www.contextures.com/tiptech.html