mouse problems

[Wolfgang]

Hi,

somehow my mouse doesn't work right anymore. I can only move the mouse 
horizontally but not vertically. (I have a PS2 mouse)

xorg.conf contains this:

Section "InputDevice"
     Identifier     "Configured Mouse"
     Driver         "mouse"
     Option         "CorePointer"
     Option         "Device" "/dev/input/mice"
     Option         "Protocol" "ImPS/2"
     Option         "ZAxisMapping" "4 5"
     Option         "Emulate3Buttons" "true"
EndSection

Thanks for any suggestions
Wolfgang