That's probably something you're going to have to talk to Dreamhost about -- but I probably wouldn't keep trying to sign up until you do, in case the first attempt somehow made it through, even without the CC code.
The panel seems to be working fine for me, but if you're still having trouble, you could try contacting them through the contact page at http://www.dreamhost.com/contact.cgi
They should be able to help finish up your order, or maybe delete whatever's in the system so you can re-submit it.
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