The US Air staff at ORD is TERRIBLE. It really seems as if they just pick random people to pick on with obscure rules.

I DID NOT check in 2 hours early for my domestic portion of my Nassau flights. No issues at all. Never heard of anything so stupid. Well, perhaps the time I was denied boarding at ORD because my bag of pretzels qualified as a carry-on. I asked to check them and buy insurance for them. It didn't go over well, but the point was made. Stupid, stupid. (the problem GA is named Kenny)