Spring RTS Engine

When I take screenshots in game (XTA or AA) with the game running or paused, out of 25 I have taken, only about 4 have turned out; the rest all show up as just a black screen.

Is there something I am doing wrong?
Does anyone else have this problem?
Edit- I reinstalled TA Spring and it is still doing it

try using the normal method of pressing Prt Scr, for some reason it works just as well in OpenGL programs as in normal windows programs. It's only directX programs or programs that bind that key that ahve the problem I believe, or possibly any program running fullscreen with 256 colours or less than your desktop..