melodyne and Ableton Rewire sync issues

Hi there

I'm experiencing sync issues between Melodyne and Ableton (the latter in Rewire mode, the former just as a simple insert plug-in) and Logic X. The two problems may be separate but my instinct is they are related.

Specifically, when I use as instance of Melodyne in Logic or Rewire Ableton into Logic everything works ok for about 10 mins but then Logic goes out of sync by 2 bars. For example, the when I transfer audio into Melodyne I hear the audio playback as one would expect but the transport playhead in Melodyne lags 2 bars behind.

I've tried reinstalling the apps, rebooting Logic and restating my computer and yet the problem persists.

Thanks

Patrick

2014 iMac, OSX 10.9.4, Logic 10.1.1, Apollo Quad soundcard and the latest versions of Live and Melodyne (Singletrack)