I made this same mistake. When you get the confirmation email from BitInstant, you will see the "API response" is actually a mtgox coupon code.
Copy and paste it into the part of mtgox which lets you redeem codes and you will have your cash. They need to update their API for the new account numbers.
Topic: Anyone use BitInstant: Cash -> Gox? (Read 385 times)
I'd give it a few days. Cash is so slow to move around, despite being numbers in accounts.
I just did a Cash -> Gox transfer. For the account number I provided the account number on the top of MtGox as opposed to the 6 digit one on the deposit page. BitInstant said order complete but I do not have my USD. Does it take Gox time to manually add funds or did I enter the wrong info and am f*cked?
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