It is still under my open orders and my BTC balance still 0 and namecoins is the little bit of change i have left after making the sell order
Hmm ... should the order have executed? The exchange rate has dropped so if you are selling it will probably be at a price too high to execute.
You can cancel and place a new order at any time. You can sell for a little below the best bid to ensure all your namecoins sell. The order matching will ensure you are getting the best prices from existing open buy orders.