In the texture panel/colors, if you use a texture with an alpha channel, if you increase the Brightness (more than 1, which is the default setting) or decrease the Contrast, some white glitches appear on the transparent part. Bug on Z transparency and Raytrace too.
Blender 2.5 29482 (it was the same on the previous build on graphicall).
OS X 10.5.8
ATI Radeon HD 2600
Description
Description