how bout the simple bug that the pitt's meshes are broke as hell, even playing on console i fell through floors dozens of times collecting those ingots and had to reload the game from dashboard for over an hour so untill the floors out in the scrapyard would load properly, not talking about out of the way places, the grounds broken right under some of those 100 ingots you need to collect for that old achievment. i dont have specific locations but i know it was never fixed, a quick youtube search probably will result in dozens of videos about it.
here straight form the wiki:
Terrain Glitches
It is a possibility that after downloading or re-downloading The Pitt that areas within the Steel Mill will de-solidify allowing the player to get outside the area of the map with ease, though when getting higher in the Steel Mill, it becomes impossible with the loss of footing higher up making certain ingots impossible to locate. This error does not correct itself nor does it change upon starting the game over or reloading a save. The only way to fix this problem is to replace your Pitt download. (On the Xbox leaving the area and re-entering and re-loading may suffice)
A popular example is that the wall directly to the right (behind a generator and yellow light stand) when you enter the steel mill is not solid and allows the PC to be in the building of the Supply Plant from the outside as it is hollow. Also, it is possible to shoot trogs from the inside where they cannot hit you.
At the Bridge you encounter at the start, if you jump onto the rocks below and start getting irradiated, then quickly fast-traveling back up, the Bridge will be un-cross able. This is because after fast traveling, it Registers the Bridge as the rocks, making the Bridge extremely irradiated. Attempting to cross the Bridge will kill you, because the Bridge now has the Radiation levels that the water has.