more troubles

hey guys and gals.  I'm have been having problems with my mouse recently.  It is an Microsoft Explorer Optical Mouse and it has been working well for about a year now.  Recently, however, it the pointer seems to stop and not want to go any farther for a few seconds no matter how much I move the mouse.  sometimes the computer freezes for a little while and i can't move the pointer anywhere after that.  I end up rebooting the computer.  Sometimes the keyboard goes with it.  It went away on its own about a month ago, but it kicked up again.  Any suggestions?  I've already tried moving my 128 mb stick over to the DIMM 1 slot and taking out the other two 32mb sticks.  Should I try running less things in the system tray?  I can usually freeze it before starting any programs.  Thanks for any help.