They are consistent for about 2 or 3 hours, sometimes more, sometimes less. But, the glitches don’t really exist on the source file, they just “appear and diappear”.
When there’s a glitch in FCP in the sequence, the same glitch will be in the source clip (still in FCP) and I will see the same glitch in the source file in QuickTime.
Then, after maybe 2 hours, these glitches are gone but new ones come up (at different spot on the media).
QuickTime version is 7.4.5
Any other footage shot in different formats play fine in QuickTime or FCP.