I just changed from a MS Wireless Mouse 2.0 to a MS Wireless Laser Mouse
6000. I was previously able to scroll horizontally with the wheel in the
right frame of a split (not frozen) worksheet in Excel 2003. Now when I try
to do this the left frame scrolls, not the right. (Yes, the right frame has
the focus.) The settings in the mouse driver seem to be right and the
horizontal scroll seems to work everywhere else.

Any ideas?