Hue problem in DX9 / ATI 9800 at night

This is a question more than a problem. I visibly see a color difference between full screen mode and windowed mode at night when I run FS9 on my ATI 9800 card. Dark gray colors appear greener than they need to be, with a distinct orientation towards the greens.I recently got a new weight-lifter style 16x9 monitor that will let me run at higher resolutions (and a trip to the chiropractor). Naturally, my first impulse was something is wrong with the monitor. However, I think the mamoth monitor just makes the effect more pronounced than on my LCD, but still looks a little green. The effect is slight mind you, but noticeable.The colors are perfectly normal in other applications including DX9 games. They are also completely normal with FS9 during the day time but get progressively greener as night time progresses. It's completely usable, but I'm looking for an explanation. The moment I leave DX mode and return to windowed mode, the greenish tint goes away. I've also checked cabling and interference, but that doesn't appear to be the case.I've played with gamma and hue settings in my ATI control panel and the Omega tweaks, but it shifts all the colors, not just the green.Using the latest drivers from ATI (actually, I'm cheating here because I normally use the Omega drivers).I'm thinking it's perhaps an issue with Z buffer encoding or perhaps a pixel shader that got enabled by mistake.Summary:- this only seems to occur in FS9 in full screen mode and at night.- only the grays seem shifted to the greeen (other colors normal including whites and light grays).- does not occur in windowed mode or with other DX applications- latest video drivers- occurs at different resolutions (1280x960 up to 1600x1200).Any ideas?