@leec87 – they asked me as well about my WP Admin credentials. No way that I would provide it to anyone. No reason for that as well. No response from them after declining to give them user/pass about the reasons for it.
Thanks! Wrote to you now.
I’m having exactly the same issue. Here’s the XHR’s request response being made on submit:
http://pastebin.com/1RU2E81b
Tried with 1.5.4 and with the newest update – no luck.