i wonder why all other u3-engine games (ut3 demo, stranglehold) run fine without the tsc tool at _remarkably_ higher framerates.
As far as i know bioshock was the 2nd game to be released using the new u3-engine (the first one was a game for children where you play a robot). So maybe bioshock is using an older version of the engine that has more bugs. Just a guess though and doesn't really fix your problem.
