There's a new version of GZdoom released. It's now v. 1.0.25. Quote from Graf Zahl's website:
This release is mostly there to address some issues I encountered while running GZDoom on Windows Vista. Of course the few new features that had been added to ZDoom in the mean time have been added as well.
Last but not least I did a rewrite of the shader code for texture warping. Hopefully this will eliminate the weird effects when dynamic lighting is used with these shaders.