No. It throws up what looks like a regular expression error (same thing twice), zeroes out the postcode and credit card details and tells you to call. I tried to put in a Canadian postcode, but it knows the Australian requirements on the entry screen and won't let you put in anything else.
I had a TK award where I called to pay, and the agent said it should work if I stored my credit card details. I just found an EY award that was a lot better, and the system accepted my stored details for the cancellation payment, but again through up the same error when I tried to pay for the new ticket. The agent said she would pass the problem on to the technical dept, but I really don't expect to see it changed in a hurry.
Anyhow, skype calls are cheap, and if you call at 7 AM Toronto time, there is virtually no waiting.