http://bugs.winehq.org/show_bug.cgi?id=30259
--- Comment #7 from Henri Verbeet hverbeet@gmail.com 2012-03-27 02:26:13 CDT --- I should mention that recommending to disable GLSL in generic appdb instructions is just about always wrong. There are two fairly specific cases where disabling GLSL may make sense. The first case is on drivers that have the nvidia shader program extensions, and where those extensions give better performance than GLSL. This is pretty much only the case for the proprietary nvidia drivers on Linux, for some specific applications. In some cases the reason it's faster is actually because the GLSL code received bug fixes that the ARB shader program code never got. The other case where disabling GLSL may make sense is on OS X where the GLSL compiler is generally just so terrible that not using it is the only way to make things work at all.
In the case of an AMD card with the r600g driver, all that disabling GLSL is going to do is to limit you to shader model 1 shaders.