Yes and i can also tell you the fix..
Some custom maps share a shader file with Nexuiz 2.0.. well almost the same, the one in Nexuiz 2.0 is much larger. So far i only noticed this error with:
space-fun.pk3 stralenex7_beta1.pk3 stralenex8beta2.pk3 stralenex9.pk3 stralenex_ctf__beta1.pk3
All maps except space-fun are now part of Nexuiz so you can either delete them or rename the files to .pk3_ so that they are not loaded and mess up the sky. divVerent created a fixed version of space-fun by just removing the shader file from the pk3 file. You can find it here:
http://hector.rbi.informatik.uni-frankf ... nofficial/