The possible cause is that your tracks is not propperly beatgridded.
Please read the Traktor manual about the beatgid.(or even better buy a copy of the Traktor Bible that explains this very well with examples)
I found that 99% of my analysed tracks in Traktor is wrongly beatgridded and this is IMO the greatest issue with Traktor
that the beatgrid is almost always wrong. Also bear in mind that only tracks with a constant BPM can be beatgridded 100% correct.
The only way to get all tracks right is to run them trough Ableton Live in order to get a constant BPM and then run them in Traktor. I have now worked all my free time for about 7 month and about 1000 of my 2000 tracks that could not be beatgridded is finished…..
//DJ Hessler