Since I upgraded to these media vp's I get a nice white bright background when I'm in mission. So nice isn't it?! No, not really.
Running currently with version nightly-r5004, but it happens as well with n-r4870, n-r4985, n-r4989 and n-r4999 as well as 3.6.9.
Opened log '/Users/dwlnetnl/Library/FS2_Open/data/fs2_open.log', Wed Dec 17 14:32:53 2008 ...
FreeSpace version: 3.6.10
Passed cmdline options:
...
-normal
...
Initializing OpenGL graphics device at 1280x1024 with 32-bit color...
Initializing SDL...
Requested SDL Video values = R: 8, G: 8, B: 8, depth: 24, double-buffer: 1
Actual SDL Video values = R: 8, G: 8, B: 8, depth: 24, double-buffer: 1
OpenGL Vendor : ATI Technologies Inc.
OpenGL Renderer : ATI Radeon X1600 OpenGL Engine
OpenGL Version : 2.0 ATI-1.5.36
...
Compiling shader -> null-v.sdr / null-f.sdr ...
Compiling shader -> b-v.sdr / b-f.sdr ...
...
Ah yes. This is the very unfortunate OS X build bug with the new shader (GLSL) feature.
At current, if you use a 3.6.10 nightly with the GLSL feature compiled in (any since about July 2008), have the graphic content that enables shaders in game from the MediaVPs and enabled on the command line you will only see a horrible white skybox/ship texture when using full screen. You can confirm this is the problem in question by opening the Techroom and you should see the ships have these odd whited out textures.
No fix is known, and the same code base works fine under OpenGL on Windows and Linux.
Your best option is to take the shaders.vp file out of /Applications/Games/FS2_Open/ (or where ever you've installed it) if it is in a standalone .vp archive. This is what I've done with the 3.6.10 mediavp beta. This will remove shaders in-game, but pretty much every other 3.6.10 MediaVP improvement will be working.
You could also disable the GLSL / normal map features on the command line OR play in windowed mode to see the shaders in effect (but windowed mode has always produced FPS underperformance to the point of making in-game too chuggy). Have a search around the forums for the steps others have taken.
There's lots of us (myself included) who use Macs and hate this problem. Unfortunately, it's such an odd bug and no one with the necessary OpenGL expereience has been able to propose a patch to the codebase to fix it yet. Not for lack of trying though.