2.5 viewport texture painting: Macbook pro difficulties

Hi!

Im having issues with the texture painting feature. Im working on a macbook pro and it seems to only happen on the mac (it works fine in windows).

For some reason it wont render multitexturing in the viewport and even though GLSL renders textures it wont let me edit the maps in texture paint mode. Ive tried this on two different macbooks and its the same on both.

Anyone have a fix for this?