They're having a hard time keeping up with the number of orders, along with MTGox's API being trash from what I have read. Send an order to support, they'll figure it out. The two times I have used them it didn't go through automatically and I had to email them, but within 2 days I had my money. I would give them a week due to the huge influx in orders.
My order is from April 2nd and I contacted bitinstant. I have received PMs and responses on the official thread claiming my issue was "escalated" but my order is still unresolved. Today my patience with the service wore out.