It seems to be a bug in the way EU is saving it... if you paste the clipboard contents into an imaging program after pressing prtsc or alt-prtsc you will get a good image.Screenshots look like the above at 1680x1050 since VU 17.0. They still work at 1600x900 though.
No fix that I am aware of at the moment.
i tried as you said but didnt fix for me anyone else fixed it without changing screen resolution >Going back a ways here but... there is a problem with the default nvidia settings which may provide insight even if you do not have an nvidia card. It defaults to a "Quality" setting which has caused problems with my systems in the past, especially with Entropia Universe and involved black screenshots and also large black areas in the distance, especially water on Rocktropia.
The fix was:
NVidia Control Panel > 3D Settings > Adjust image settings with preview
The default setting is "Let the 3D application decide" PLUS the slider under "Use my preference emphasizing:" will be set to "Quality"
You need to activate "Use my preference emphasizing" and change it to "Performance" THEN change it back to "Let the 3D application decide" (don't forget to apply the changes each time)
This fixed the 2 problems I mentioned for me and was mentioned in the support site somewhere, somehow. As I said, If this does not directly apply to you, perhaps you can glean some information from it that will help solve your problem.