Mouse stops responding in Mac 9.2, may point to other problems

I'm not an apple user by any stretch, but I know computers, as I've put much of my time into the hobby. However, this problem stumps me.

At work, on my Mac G3 unit (running OS 9.2), my mouse will occasionally, but suddenly, and without warning, die, for lack of a better term. It stops responding completely, clicks and movement. The only way to restore its usage is to unplug it and then plug it back into the USB port.

This is a very annoying problem, as it happens frequently (sometimes 20x a day) and I think it may be leading to other problems, like system crashes, which happen about 3-4x a day. I even tried force quitting, but I noticed my mouse isn't responding when I do a force quit, so I can't force quit out of the current program I'm in (if that's even the problem).

I think the crashes and everything that's going wrong with my work computer comes back to this random mouse crashing. Any suggestions? I'm using apple's Pro Mouse, the see-through deal. Any help offered would be accepted most graciously.

To reiterate, this problem happens at a whim. I can be dragging a window, opening a menu, or just moving my cursor across the screen, and my mouse will lock. Again, help, please.

Bumping. Problem still relevant.

Is the mouse connected to the computer or to an unpowered hub and then to the computer? Device dropout is often a symptom of too much power draw on the USB port.

It is connected through the usb port on the Keyboard, which, I believe, is connected to the usb port on the PC.

The first thing is to isolate this to a hardware or software problem. First, try a different USB port on the computer and on the keyboard. If that doesn't resolve it either take the mouse and keyboard to another computer or use a different mouse and keyboard on your computer.
If your computer continues to have the same problem with a different mouse and keyboard then it is related to the computer; it could be a problem with the USB port, an issue with the system or (rarely) other hardware or software that interferes with the USB bus.
If the problem stops on your computer with a different keyboard or mouse connected then your mouse or keyboard is defective. You can then try it with different combos to isolate it to the mouse or the keyboard.

Thanks for the diagnostics tips. I was hoping this was more of a Mac-specific issue, but I suppose it's just one of those old computer quirks. Unfortunately, since this is my work, it's a little more difficult for me to go through all the steps, but I'll certainly try now. Thank you much.