Garry's Mod Black Screen (Mac)

When I load the game, the screen is black. It isn’t frozen, I can pull up the in-game Steam menu, and I can hear the sound of the text when my mouse rolls over it. What can I do?

Late 2006 MacBook White
2.0 GHz Core 2 Duo
GMA 950

I know the specs are terrible, but I can play Gmod on windows, just not Mac.

On a separate note, Portal gives me a seizure inducing flashing at the title screen, are the two occurrences related in some way?

Gma 950

that’s the problem

Try running in a window?

That occasionally happens to me on Windows, but if I get a game started, it stops doing that.

alt tab out then back in… thats what i do

(or, Change tabs in chrome,
scroll over a another program,
minimize + resize)