14 months later - still no answer? I am having the same issue, and it's with a large number of files it seems. I can't pinpoint why, it's happened to seemingly random files. Some are fine, some experience playback issues - ALL have been run through the latest RekordBox and it's only after doing that, the tracks started to play up.
They will skip, jump back 4 bars, jump back to start, sometimes the clock will jump back in line with it but other times not. I also noticed that if a track is seemingly playing smoothly, and I try to use an effect, it isn't synced on the beat, so it's as if the software has not recognised the time data/BPM. But it is displaying it, correctly.
Any answers out there?
