Wireless mouse suddenly losing signal/range?

I have a logitech wireless mouse/keyboard combo (not even sure of the model..it's about 5 years old) and the mouse has suddenly (within the last 24 hours) lost it's range almost entirely. It was working fine one moment and then it began not moving/responding when clicking. I've determined that the receiver is fine, as the keyboard still works from over 10 feet away, however the mouse won't respond if it's further than 12 inches from the receiver. I've tried it on another computer and the results are the same...interference isn't an issue, it's the mouse itself. I've tried changing batteries, I've cleaned every nook and cranny to make sure something isn't somehow mucking up the internal radio...am I stuck with having to buy a new mouse? Like I said, the keyboard maintains its range, meaning that the receiver itself and interference aren't the issue.