Mouse scroll wheel speed far too sensitive

In my Crunchbang installation with X11, openbox, my wireless usb mouse is listed at both /dev/psaux and /dev/input/mouse0. It's working fine apart from the scroll wheel, which although active, is far too sensitive. I'm thinking maybe the kernel is raising double the scroll events that it should be? Not sure what to check out even if this is the case? I tried adjusting sensitivity via lxinput but it affected everything on the mouse apart from the actual scrollwheel. xinput list ⎡ Virtual core pointer id=2 [master pointer (3)] ⎜ ↳ Virtual core XTEST pointer id=4 [slave pointer (2)] ⎜ ↳ Microsoft Microsoft® Nano Transceiver v2.0 id=9 [slave pointer (2)] ⎜ ↳ Microsoft Microsoft® Nano Transceiver v2.0 id=10 [slave pointer (2)] doing - xinput test 9 results in expected mouse motion events (but nothing for button clicks/scrollwheel) - xinput test 10 results in unknown class with no events fired.