I'm guessing you're using a hexed exe to play without game disc? If so you should have read this: The Following cracks seem to be working BUT they all have the "Shaking Camera" Problem
You'll have to play from your original game disc until a proper hexed executable is released (don't hold your breath though).
If you are playing from the original game disc then I don't know what the problem could be, can't be good though.
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