I've checked in some patches to support the wheel of most current mouse 
devices in the CVS source tree.

The patch supports 7 mouse buttons in total, with button 1-3 as regular ones 
4,5 wheel up and down and possibly 2 more for further use.

The default behavior is scrolling in the message windows, but additional use 
may be defined with the buttonmap values d-s to prevent compatibility 

BTW: Any patches pending? I've currently some time for releasing a patch.

Have fun,