Black viewports in only one mod, rest work fine

[disturbed]

Picture - Problem I'm having
Picture - Configuration for mod
Picture - More configuration

When I open Hammer to make a map for my mod, I get what is shown in the first picture.

I made the mod in the 2007 engine, then made a new config for 2009 so that I could work on it in Hammer. This process worked fine with a different mod I started about a month ago.

The configuration for the mod that doesn't work is identical to the one that does work.

Everything else in the Source 2009 category works. I've tried re-installing Source SDK, Verifying Integrity, making another new config, etc.

Any help?