Same problem here. I deposited money 41 hours ago and still have not got it. It's next to impossible to get their support people to respond. MTGOX told me that someone at Bitinstant had used my redemption code and that they (Bitinstant) would have to issue me a new code. Pretty hard to do when they won't even respond to my inquiries.
I'm having the same issue with getting my funds activated at MTGOX. It tells me "This code cannot be redeemed (non existing or already used". It's been 24 hours.