I'm reopening this topic since it was closed by Sunny:

"Brown stuff is random, sometimes you see less, sometimes more.
Not a bug. "

Agreed, not a bug. That's why thread was marked as a "hack???"
However, brown stuff in pictures is picture corruption, and doesn't appear randomly or anywhere else in the game.
The fact that "browness" appears to a random extend each time, it is just the wrong interpretation by the software.
You see, it doesn't quite understand the format, and each time tries to do its best.
Probably not a hack, but the result of a 2 much overused file from the disk, and a couple of bits going bananas
Regardless, it should be replaced with a fresh copy, both for aesthetic reasons, and for the well being of the software