When you leave Farglow, end the conversation yourself before it finishes automatically, and the cutscene should start properly (it has for a couple others that have run into that problem, anyway).
Have you installed the patch? I though that issue was suppose to be fixed (I think just the non-US Xbox versions are still waiting on the 1.03 patch).
Try running the game as admin in XP SP3 mode and disable desktop composition in the compatibility options (for Vista/Win7).
If that doesn't help;
First Aid Kit for Divinity IIFirst Aid : when Div2 does not start or crashes