Show up for a New Haven to PHL flight on Saturday (1/8). Ship arrives early (DH 8). Unusual, in that a crew change occurs at 3 in the afternoon. Anyway, the new Captain, an older fellow by Express standards, goes out to the plane, comes back looking unhappy, and disappears with a bunch of papers, charts, etc, Next thing you know, the co-pilot goes out to the plane, climbs on, and pulls the stairs. Much time passes. About 40 minutes past departure, the agent comes back, and announces there is a "documentation" problem, but won't elaborate. In the interest of time, I wil roll forward 2 hours. We are still there, all connex broken. Calls to the CP desk don't provide any info. At that point, the phone at the gate rings. Call for the Captain. He comes off the plane and takes it. I overhear the conversation, which seems to suggest the plane has certain paperwork on board, but it's Piedmont, and these guys are Allegheny, and they can't fly unitl they get the correct stuff. Apparently the companies pool aircraft, or something. Anyway, I hear him say it's happened twice in the last few weeks. Something has been taken off, and replaced with stuff from another carrier. Thanks to no information, and false promises of imminent departure,, we have lost all alternatives, until somebody figures out we can still make a flight to CLT from Hartford, 60 miles away. They offer taxi vouchers, only no driver will take them because the company is so shaky. Avis is still open, and in the spirit of the moment, rents me a compact car for $110. I drive through sleet and ice, somehow make the flight, and 10 hours later, arrive in FLL, 40 miles from my original destination (PBI). Big night for the car rental guys. What is going on? If that plane was illegal, how did it get up there from Philly? More to the point, where was the company on all this, and how can it survive when even the taxis won't take it's paper? Also, if it was serious, how did it not get caught by somebody, and does that kind of thing carry through to maintenance? Crazy..and scary.