Very Computer

I have an Intellimouse PS/2 running through a KVM into my Linux box. For
the past 20 days, it worked fine, no problems.  Then yesterday, the wheel
stopped scrolling up.  Still scrolls down, just not up. When I switch back
to the other machine, it works in both directions.  I've tried editing the
XF86Config file, restarting X and gdm, restarting gpm, all to no avail.
Any ideas?

Relavent XF86Config parts:

Section "ServerLayout"
        Identifier     "Anaconda Configured"
        Screen      0  "Screen0" 0 0
        InputDevice    "Mouse0" "CorePointer"
        InputDevice    "Mouse1" "SendCoreEvents"
        InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "InputDevice"
        Identifier  "Mouse0"
        Driver      "mouse"
        Option      "Protocol" "IMPS/2"
        Option      "Device" "/dev/psaux"
        Option      "ZAxisMapping" "4 5"
        Option      "Emulate3Buttons" "no"
EndSection

Section "InputDevice"
        Identifier  "Mouse1"
        Driver      "mouse"
        Option      "Device" "/dev/input/mice"
        Option      "Protocol" "IMPS/2"
        Option      "Emulate3Buttons" "no"
        Option      "ZAxisMapping" "4 5"
EndSection

Thanks,
Rob