Here's a bug that was found in Thief 3 Deadly Shadows by Steerpike over at Iom Storm's Forum.

The bug I just discovered tonight (which will effect everyone, including XBox players) will make me wait for a patch. Yes, its that bad.

You see, in Thief DS, the difficulty mode affects the following elements of the game:

objectives number of guards AI perceptiveness * AI combat ability *

Thief 3 Deadly Shadows Bug