I think someone is trying to manipulate PMC's price downwards..as I've noticed that after taking down a lot of the buys they then post quite a low sell order. So at the moment a sell is posted at 47...with the next one being 61. So anyone who is not watching too carefully will sell low too.
As it's such a small exchange I'm guessing there isn't much we can do about it except hope that their endgame is to buy cheap and sell higher.

Or somebody's left a partial order from selling. Though the market is still weird, and it seems to happen way too often.