Since Blender 2.63 texture fonts are not working. It look like they are using vertex colors. After a restart of Blender the colors are changing.
Since Blender 2.65 the multitexture mode has the same problem, if the alpha is enabled in the texture panel.
Blender 2.63 singletexture mode not working
Blender 2.65 single and multitexture mode not working
Windows XP 32 bit
Nvidia GeForce GTX 460