I'm not getting sky on a few maps. I don't have any mods installed except MBII, my Nar Shaddaa Streets maps, and Link 3.0.
I'm not getting sky on: seige_desert mp_ctf1
Those were the two i noticed, i don't believe im missing sky on any of the other ones.
specs (if you need it) 2.0 GHz AMD Athlon X2 dual core 1Gb ram 256MB nVidia Geforce 6150LE (with current drivers)
Instead of a skybox, are you seeing a black wall/"sky"? If so, that's because you have your settings on Low Quality. Change it to High Quality, see if that helps.
Also, make sure none of your shaders are clashing.
Oh crap! Thank you! I had a conflict between my Nar Shaddaa Streets mod and the base assets .pk3. It looks like I had put the "scavenger.shader" and the "skies.shader" into the narshadda.pk3, so that was causing the conflict. But that causes a problem for me because with out the skie.shader in the narshadda.pk3 then the narshaddaa maps don't have sky, but the rest do.