I'd say bad brakes. I have a milk crate bolted onto my rack, so if the seatpost failed it would bend back about 2 inches and I'd be sitting on the milk crate. That seems more survivable than a full speed unstoppable blast into the middle of an intersection .

<sigh> I'm a little irritated at Wissahickon Cyclery. They're really nice and seem knowledgeable and carry decent bikes, but they NEVER call you back.