I'm on windows vista (32 bit) running nexuiz 2.5.1.
When I take screenshots now, it results in an all white jpg.
I'm taking a screenshot using the "screenshot' command.

I'm using low settings.
I have an nvidia 9800gt.

I checked these cvars:
scr_screenshot_gammaboost 1
scr_screenshot_hwgamma 1

Those are default.

I have taken good screenshots before on this computer, but that was using 2.5 and also an Nvidia 8600gt. I don't have Nexuiz 2.5 on here anymore, but I might grab a copy of that somewhere and give it a shot.

all the times you have white sshot?

scr_screenshot_hwgamma
I know must be set to 0 to have a shot as you see in game
with value 1 I had overbright (but no all white)

PS
I have sometimes an all black shot. Seems the first shot taken when start a new game but im not sure.