That could definitely be it. I should also probably mention that the bike with this problem is not my regular bike, it's a tall-bike. The top frame isn't lined up well with the bottom frame, so the chainline is pretty radically imperfect, which could maybe be compounding the issue. Regardless, I'm going to get a new crankset, make sure it's the right size, fiddle with which sprocket the chain sits on the cassette, and not tighten the crank bolts down too hard. Thanks!