Ah! That was it. I have a BTC100 Ask. I didn't realise that you had to have those covered from in-market balance. I'd thought one of the reasons for requiring a bitcoin address was to be able to confirm trades could be covered by bitcoin trackable through the blockchain to that address.

Curious. Well, I have more in my account now, and it's letting me withdraw. The error message definitely specified a minimum (though it was slightly ambiguous whether the minimum was balance or withdrawal amount). As I can now withdraw, I can't reproduce the error message, and only have memory going for me. *wry grin*

By the way, the new currency-specific tabs on the markets page are pretty awesome!

What's the minimum withdrawal volume from the market? I purchased BTC100, but can't get it out to actually use for trade because I don't have enough in there.