The way I use to solve the problem in my old setup with my RandMcNally was to wait for the mouse to jump, then pull the power port on it (PS2).
Goto device manager and then right click and disable.
Then re-plug the ps2 power port for the gps and no jumping.
After no system changes, the mouse would do this two more times after certain reboots. I would repeat the steps above and it would fix it. I would do this a total of 3 times and it seemed to stop it. I ran my CarPC install without formatting for 1-1/2 years and the mouse never jumped after the disabling 3 times.
If you use hibernate though, you may only have to do this once.
Unless your system reboots and possibly detects it as a serial mouse.