graphic problems - fog and light on textures

[sybesis]

you could try to turn off every effect.
If the problem is resolved turn on some effect then test if the problem come back.

I believe your graphic card isn't the problem. May be the driver. My nvidia driver is at version 173. Who know they may corrected some bugs with alpha and or glsl. But i doubt that. Because this kind of bug seems critical. correcting a bug like that 3 year after the release of your card seems "bizarre".

While on the other hand. the probleme could be something like penumbra not able to find the file that does the alpha test on the particle. or your card handle GLSL or CG strangely.