Factual error: At the end, when Cyndi Lauper touches the glowing pyramid, goes into a trance, and starts translating the inscription, Jeff Goldblum pulls her off and she doesn't finish it. One of the bad guys says that what Cyndi already said will be enough to help him decode the rest and that it's just a matter of "cartography" now. He should have said "cryptography" (skill of decoding secret writings) and not "cartography" (which has to do with making maps).
Audio problem: When Bourne rescues Marie, he fires a silenced pistol at the man who was trying to rape her, but the sound is of an unsilenced gun. (01:01:10)
Continuity mistake: When Nanny Taylor is discovered in the bath and Poirot is leaning over her, her plait is first across her chest and then it is suddenly along her arm. This is most evident in the flash-back scene at the end of the movie.