Audio falls out of sync on .avi files played in Miro 1.2.7, but plays fine in Quicktime Player (7.5.5)....why?

an .avi file of an 90 minute movie, encoded in XVID, with audio in .mp3 audio,
loads into Miro 1.2.7, but after 5 minutes of playing, the audio drifts and never stays in sync.
Same video opened and played in Quicktime 7.5.5, plays fine from start to finish,
using Perian 1.13 to decode the file for playback.

Is there something to use to get this to play correctly in Miro?
I recently updated VLC to 0.9.8 and it plays the file ok as well.
what gives?

OSX 10.4.11, 2 GB of Ram, Miro 1.2.7, QT 7.5.5, Perian 1.1.3, VLC 0.98.