Leaping Mouse syndrom

In some rare cases PC thinks that GPS and other NMEA data, assigned to serial port, is Microsoft Ballpoint Mouse. In this case Your mouse goes nuts and starts jumping to random locations on the screen and off. At least, my Dell Latitude’s mouse started act like crazy.

Solution:

1. switch GPS and/or other NMEA data sources off, mouse  calms down
2. go to device manager (Control Panel, System)
3. find Microsoft Ballpoint Mouse under Mice and other pointing devices
4. disable it (right click, disable)
5. switch GPS on, mouse behaves now

Good luck!