Mouse problem - Optical mouse with PS/2 - USB connector won't work

I've tried searching the boards to see if this has been addressed
before but can't find the help I need.

I was using an optical mouse with just the PS/2 connector for about a
year and didn't have any problems. Eventually, it would "skip" past a
few pages when I was going back to a previous page on the Inernet so
replaced it with another optical mouse, this time with a USB to PS/2
adapter. Everything was fine for a few days and then when I booted up
the arrow wouldn't move - it would just sit there in the middle of
screen no matter how much I moved the mouse. The previous optical
mouse had a red light on when I used it, the new one didn't - at
when I checked after it wasn't working.

I brought a mouse home from work, again with the USB to PS/2 adapter,
brand new, and it wouldn't work either.

I've got a mouse with the roller ball connected now - with just the
2 connector - and it's working fine.

I was thinking it must be something to do with the adapter, but it
work for awhile.

Has anyone had similar problems and found the answer? Any help is
appreciated. Thank you.

I have a Dell with Windows XP Home Edition - just in case that's