It's quite possible this is just variance. But, still good to examine your play. I recently went through a heads up cooler and found some problems when I examined the HH. I also found that I experienced quite a bit of bad luck.

Take a look at the SB pushes to make sure you're really in push-any-two situations. Do the same with your BB calls -- if your opponent's pushing range is wide, you might find you're not calling often enough.