The seam that runs from the top opening of the bootie to the top of the toe has been slowly unraveling.  When I got the shoe I thought to myself "Gosh, that looks like a part of the shoe that's going to take a lot of structural stress... did they reinforce it somehow?"  It didn't look like they had, and yes, the stitching came apart very quickly thereafter

Luckily, it's a very easy seam to fix, but it's still annoying.