i dom't even use my mouse, sine my X52 has a mini-joystick which is used as the mouse. luckly im left handed, so it's easy for me to convert to the left handed-ness.
i use a wireless labtec mouse/keyboard combo.
if it's a wireless, those tend to run low on battery quick. i'v had this keyboard since november, and i've replaced the battery 6 times. if not, it may be a cable issue, IE: faulty wiring or bad connector. my policy on this is if it costs more to fix than to replace, then replace it. aways a pretty good policy.

Ramos