Hello,
At least if XWin is run on notebook, there might be the problem that cygwin incorrectly detects the number of available mouse buttons. This may be the case especially if a 3-button-wheel mouse is attached to a PS/2-port of that notebook, because the internal PS/2-port emulator intermixes external mouse events with touchpad events. In this case, cygwin detects only 2 buttons (I assume the two touchpad buttons), while it should detect 3 buttons.
This is usually not a real problem, because cygwin seems to add (by default) 2 buttons (for wheel-up and wheel-down), resultin in a total of 4 buttons. But if the user wants to use the wheel of the attached wheel mouse, the wheel-up-events are properly scheduled to the X clients, but the wheel-down-events are not.
If one could manually specifiy the number of available mouse buttons (e.g. by command-line), this problem could be solved. Additionally, a related problem could be solved, too: Even if XWin correctly detects at startup time that there are only 2 mouse buttons, users might plug in a mouse with more buttons later on.
Cheers, Xuân.
