When I press and hold the Shift or Ctrl keys, the game will temporarily stop accepting anymore input (mouse or keyboard). However, the units continue to move and fight. This happens when doing shift+mouse to select multiple units, ctrl + mousewheel, etc. This will even happen if I just hold down the shift or ctrl key in isolation.
After a little experimenting, I have determined that the severity of the problem is linked to the repeat rate I have set in the Keyboard Properties from the Windows control panel. The lower the repeat rate, the less severe the problem. At the highest repeat setting, my computer will start beeping repeatedly (not from the soundcard, but from the computer speaker).
1. Version: Battlefront 1.01
2. Processor: AMD 64 3000+
3. Video: NVIDIA GeForce 7800 GS driver: 6.14.0011.6218
4. Computer memory: 1 gig
5. Operating System: Windows XP
6. Keyboard: Microsoft Wireless Natural Multimedia Keyboard