My wife made a Quicktime video recording using an auxiliary microphone connected via USB (griffin imic) and the built-in camera on an iMac (core duo, running latest Leopard). She imported into iMovie8 to do some videoclip cut and pasting to produce final video. This was then shared so that she could import into iDVD. When she plays the recording (in iMovie8 and in the iDVD project) there is a noticeable lag in sound. Picture and sound are not synched. Is there some setting somewhere that we may have missed?

She has done something similar before using the on-board microphone, so I suspect that there is something we're not setting up correctly in the imic connection.