I saw something strange. I had some glitch in the begining of a fade. Upper layer(track) = track1 Lower track = track2 Fading from Track 1 to Track 2
Track1 ================== Fading \/ \/ \/ \/ Track2 X=============
the single frame you know about was at point X.
When i moved the track 2 to an point earlier like
================== \/ \/ \/ \/ X=============
this single frame flashes again at point X.
So track 1 was playing but every time when a clip starts below, the first frame of this clip flashes up for one frame.
I saw something strange.
I had some glitch in the begining of a fade.
Upper layer(track) = track1
Lower track = track2
Fading from Track 1 to Track 2
Track1 ==================
Fading \/ \/ \/ \/
Track2 X=============
the single frame you know about was at point X.
When i moved the track 2 to an point earlier like
==================
\ / \/ \/ \/
X= ======= =====
this single frame flashes again at point X.
So track 1 was playing but every time when a clip starts below, the first frame of this clip flashes up for one frame.