There are two distinct things you can/might have to do to correct a beat-grid.
1) Assuming the software got the BPM right, then setting the first down-beat should solve your problem. If it doesn’t, you move to the next point.
2) If it gets the beats wrong you may have to either expand the grid or shrink it. Thanks to nice wave-forms today this easy to do. You see if the grid is wrong, just setting the first one right is not gonna help. By changing the grid itself, you can correct that problem.
As Bill said, not all tracks are steady (quantised) beats. And Traktor is known as the worst software for gridding tracks with varying BPM. So if you have tracks like that, tough luck as Traktor won’t be able to handle it correctly. Furthermore NO DJ software gets it right all of the time. Anywhere from 70-90% of the time correct is reasonable.
If you feel you are restricted by this, then it really does pay to invest time and effort into the art of manual beat-matching. Sync is a nice tool to use and clearly can only be used properly with correctly gridded tracks, but it is still that, a tool. If you are dependent on any tool as a DJ (clearly outside the obvious of having some kind of platform to allow you to play tracks and mix them), then you might want to revisit your priorities.
We are not judgmental here about using sync, we think it’s a wonderful tool that can help free you to do other creative things, at the same time we do believe any DJ worth his/her salt should be able to do manual outmatching, for all those times that a synced beat-match is just not in the books.
Hope that helps some.
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