Que not working properly

When I first load Traktor I have no issues. Cue up a track works fine. The more I play it starts behaving weird. Mid set Ill attempt to Cue & It will load the track that is playing on deck A to B. If a track is playing in B it will tell me deck is locked & wont load. I did find a loop hole that is allowing me to cue. If I hit browse to seek a new track. While Im in my library view I can both turn on & off the cue function. As soon as I go back to deck view I have the same issue. This has only happened since the most recent software update. Im on a Mac running snow leapord. Anyone else have this issue or Know how to resolve it?