Happens with and without mods, vanilla ini, so I'm not going to list my load order.

Anyway..the sun turns black if I look at it. If it's partially covered by a building or something, it doesn't turn black.
Using vista/goty morrowind, tried running in XP compat' mode, made no difference.
nothing wrong with my gpu, etc, either.

specs:
e4500 (stock), 2gb ddr2 667 ram, hd4850 512mb, asus p5l 1394-vm

Try this file it's linked to in this thread, it worked for me.

Thanks! Now I can finally play my fifth-favorite RPG of all time without going crazy over the sun.