I'm pretty sure I was using the latest version but I made sure to download and install it again anyway, but it's still doing it. I tried turning off everything *except* the post-processing, as well as just fiddling with all sorts of permutations with the options in general, but nothing seems to affect it.
It seems like it's trying to constantly get brighter in the external view, then if I switch to internal it gets reset and starts to climb in brightness again. Using time acceleration gives it a kick and causes it to increase faster when I switch back to normal time until my DG looks like it's about to melt (which would look awesome down around Mercury, and I assume is the intention).
And yeeeeeeeeeeeeeeeeeeesssss I have all the latest drivers for everything, and even tried both the latest stable video drivers as well as a just-released beta, and don't have my graphics card options set to do anything to Orbiter from the outside.
Specs are:
Win 7 Home x64
AMD Phenom II x6 1100T @3.8
GTX570 (I *have* heard this can have some problems with DX11)
8 GB DDR2
I don't doubt you've fixed it but there's probably some little box somewhere I'm forgetting to (un)check, or at least we've found it's symptomatic of something deeper. I tried doing a few searches for the issue to see how anyone else might have solved it but search has been working weird for me lately and not turning up posts I know for a fact exist.