I may be late for the party but just in case you don't know. The DVD version of the Angel of Death, Broken Sword 4 has graphics issues with multi core PCs Win7 64 bit and so forth.
It only works with the Angel of Death version.
If you install the disc the characters will render in black as well as some objects. The GOG version does not have that problem. But GOG says do not buy theirs if you have the disc. They spoke to Revolution about the issue and there is a patch available. The fix came out in Sept of 2011.
Here is a link to two files.
Revolution The first file is a patch and the second is a replacement executable file. You need the new executable because the old searches for the DRM. It removes the DRM and the disk is no longer needed to run the game. Together they correct the graphics problem. The downside is the saves are connected in some way to the DRM so removing the DRM messes up saves.
I just installed the game to see the bad graphics and make a save. I did not want to see that long intro again. Ran the patch replaced the execute file and the save I just made did not work.
The game runs without the disk in the drive and new save work ok. Any made save from previous plays will not work in the GOG version because those old saves are tied to the DRM and GOG is DRM free.
Thanks to GOG your DVD can be drm free as well.
I thought I'd pass this along in case anyone had that problem and perhaps save a purchase of a GOG replacement. I bought the GOG version anyway just to have a back up. It will be interesting to see if the DRM free disc version saves will work in the DRM free GOG, who knows?