On your programming computer, open a browser and go to
http://10.xx.yy.11
Make sure xx.yy is your team number.
Login as FRC/FRC (log/pass)
Find the advanced image adjustment options.
Find the "exposure" settings
Option 1:
Find a preset that works for you
Option 2:
Select "Automatic"
Shine a light into the camera, and move the light around until the camera auto-adjusts to the desire exposure time
Once adjusted, select "Hold"
Your exposure setting should now be persistent - even between power cycles
There is a great camera tutorial by HOT - 67, which details the process. I can't find it right now, as I'm on my way out to run errands.