Which cutscene?
There are a couple cutscenes where the game can have a problem if you take quite a long time getting there (including time the game was paused), but there is an Xbox patch about to be released (in the next week, or so). see
hereIf that is not the issue... One person with D2:ED had a problem with a cutscene playing off the DVD which didn't occur with the game installed to the hard drive.