There have been a number of incidents of transactions with weird very high fees (e.g. 170 btc) in the last few months. Some people had assumed that these were just miners fooling around with their own money (perhaps a retarded kind of money laundering), but I saw one today that was that I know broadcast long before it was mined (because I, and the other p2pool miners were greedily looking at it in out memory pools):https://blockexplorer.com/tx/7b3cb56b11507c45930825af4bb5aecfc6904840834cea86413743af0066fe4f
The interesting points here is that the fee is some not round value (doesn't look like someone manually punching in a high fee), that the transaction appears to still have a change output, that the fee is much larger than several of the inputs (so they could have simply been dropped).
I'm concerned that there might be a client out there with broken coin selection code. Thoughts?