If you skipped a tooth, you would see a very noticeable split in the fins. Yak makes a couple of excellent points: First make sure your pedals are in similar adjustment positions! Second, note that it's rare to jump a sprocket tooth with the newer style plastic sprockets, which I believe you have. It tends to happen more with the older style Drives with stainless steel sprockets where the adjustment settings are more critical. Finally, it's also rare but possible to have a broken sprocket tooth (factory defect) -- take a close look at the individual cogs as you rotate the fins.
If it's a small split, you may just have a bent mast. If so, it is best to remove it before straightening it. OR, the fins could be slightly out of adjustment from the factory. In that case, you can re-center either mast by adjusting the chain/cables (loosening one side while tightening the other).
Here's a link that shows more details on adjusting the cables:
http://www.hobiecat.com/community/viewtopic.php?t=6418