That is what we thought too, but after talking with the aircraft crew, it really was a maintenance issue. Judging by the way the pilot landed at MIA, it is no wonder they had a flat tire prior to picking us up in Cozumel!!I think that "mechanical problem" is a catchall term that could mean just about anything. I think it's spin doctoring to make the delay more palatable to inconvenienced passengers; no one wants to fly in a broken plane.