Pops on audio playback

I have an intersting problem occuring.
In cubase 6 When i play back a bass track i get a pop/crack.

This only occurs at a point where there is punch in and ONLY happens on the bass guitar track. Rerecording did not help and it still only occurs at the point of a punch in.

I have adjsuted latency to every setting and the effect is identical.

any ideas?

Well, use a crossfade or fade in then…