if ya could give me more info  I could help ya.
but I know that there are some levelbugs on som maps .
they start from the level where you are a monster.
from the moment you have to go into the mansion the buggy part is over.

the awesome part about sin I found (exept the sound and enviroment .)
was that it had a gameplay.
slower and realisticer then quake but still faster then sof.
almost like half-life just a bit faster.