You'd probably find more help in the actual iPhone sub-forums...but it probably fouled up during your update (for any one of a hundred reasons). I'm not exactly sure what your last post meant (by hacked, do you mean jailbroken? Unlocked?), but a fresh restore would be your best bet at this point as the camera is not an issue that is very common (reflecting your case where it just stopped working). Sync it up, restore it fresh and see where you stand on your camera issue...past that, you've literally given us so little detail it would be impossible to really help you in any way honestly.
Best case you restore and it works again...worst case you have a faulty 3GS that would have to be replaced in most cases (though i highly doubt that).