I too never received my funds. The confirmation email spat this out:
OrderID: 87bab701-19d4-4c4f-8534-f0b29b5387cc
EventID: a41c94af-812e-4c7d-b76a-f1eb70d588cd
DestAccount: TheWorst
QuoteID: 1c8df049-2ee5-456d-bcb4-82e98b904179
User: SYSTEM
DestExchange: mtgox
eventtype: Order executed
EventSentAt: 1363902339.16
APIResponse: {'Mtgox 200 error': "{u'error': u'Must be logged in'}"}
FundsSent: $336.035 USD
Please get this fixed. I would also like the BitInstant charges back as well for this order, as the service I was paying for was not provided as advertised. I'll definitely think twice about using this service again. 24/7 support my ass.