Hi Damien,
Suggest you take a look at setting up the driver as follows:
http://www.mvps.org/dmcritchie/excel/mouse.txt
which contains some other specific overrides for other applicatons.
MS Excel for Windows -- Mouse Settings
Customize
Windows START, Settings, Control Panel --> Mouse
Left Button: Left-click (global/default)
Right Button: Right-click (global/default)
Wheel Button: Enter (global *override*)
Large Thumb Button: Back (global/default)
Small Thumb Button: Forward (global/default)
Excel: Tools->Options->General->"zoom on roll with intellimouse
keep this off or you won't be able to use mouse for
a vertical scrolling, you can still use Ctrl+wheel to zoom in/out.
VBE problems with scrolling: make sure you do not have
exceptions in Control Panel, Mouse, General, Advanced
or for some older drivers there is a tab near the end
[but that would mean you are not current]
Latest Microsoft Mouse Drivers:
Microsoft Mouse | Download -- IntelliPoint Mouse Software
http://www.microsoft.com/hardware/mouse/download_ns.asp
works with Logitech mice as well but will disable itouch keyboard features
For non Microsoft mice, if MS drivers don't work either, and the MS drivers
don't work either see freewheel
http://www.geocities.com/SiliconValley/2060/freewheel.html
Although the freewheel solution Chip mentioned is frequently mentioned, I don't have it. The mouse must be active in the Windows
taskbar (next to the clock). Actually I have it hidden thanks to some startup application.