Offizieller Kommentar
Hey Dave,
Can you please check that you have analysed the songs in the correct method? If the song has a consistent electronic tempo, it should be analysed in NORMAL mode, but for songs with a live drummer (like rock or disco), you should use DYNAMIC mode. And once you've verified the analysis is correct, check the beatgrid is on the beats of the song.
Finally, it's worth noting that if you're using MP3s with a variable bit rate encoding that there's always a chance they may not play back at a consistent rate.

