Mouse dead after reboot loading YaST magically fixes it

Greetings.

I have the following strange problem with my system. It's occurred on two different machines (with the same mouse) running SuSE 9.0 and SuSE 9.3.

I have a Logitech MouseMan Optical USB mouse. According toetc-X11-xorg.conf, everything seems to be correctly configured (see below). However, when I first boot my machine, the system does not respond to the mouse at all. I get the mouse pointer, but moving the mouse around or clicking does nothing.

However, if I then use the keyboard to load the YaST mouse module (yast2 mouse), the mouse suddenly starts functioning. I don't even have to select a particular mouse model from the list or hit "OK"; the mouse starts working as soon as the YaST window pops up. I just hit "Cancel" and get on with my work.

If I ever reboot the system, the mouse will stop working again and I have to repeat the above.

Anyone know what might be causing this? A colleague thinks that perhaps a particular USB module is failing to load on boot, but neither of us knows how to verify or fix this.

Regards, Tristan

Excerpt from xorg.conf:

Section "InputDevice" Driver "mouse" Identifier "Mouse1" Option "ButtonNumber" "5" Option "Buttons" "6" Option "Device" "-dev-mouse" Option "InputFashion" "Mouse" Option "Name" "USB-Mouse;MouseManPlusPS-2" Option "Protocol" "ExplorerPS-2" Option "Vendor" "Logitech" Option "ZAxisMapping" "4 5" EndSection

Section "ServerLayout" Identifier "Layoutall" InputDevice "Keyboard0" "CoreKeyboard" InputDevice "Mouse1" "CorePointer" Option "Clone" "off" Option "Xinerama" "off" Screen "Screenfbdev" EndSection

--