hardware once I'm confident that I will keep it in my system. Buying the backup as soon as possible tends to insure that both have the same version of internal circuit boards and drivers. You really can't expect them to keep these things around for decades and not update the manufacturing/programming.
Next some questions. Have you updated the drivers? Have you checked to insure all the buttons are working through the XP Control Panel/Game Controllers? Is Joy2Mouse loading the correct XML file? If everything else is working and your RR keytbl.ini has all the appropriate codes, try the attached J2M file and see how it works for you.