In 1.6 Engine OS Beta, some tracks will play at double speed, the temp display is correct however the music plays at double speed. As soon as the pith fader is touched the music returns to the correct play speed. The effect is has happened randomly when playing analysed Drum and Bass (175BPM) on continuous playback.
Why not make a proper bug report with accompanying video?
If you’ve been using the auto-sync function check the manual for how to engage and disengage the controls.