I would clear cookies and log back into GMail (to help with CAPTCHA) right at 10:59 then @Snayberry.
Today, I was "banned" at 10:30 and like 10:50 but if I cleared cookies immediately after those tries, I was able to get through.
This also works for me sometimes, clearing cookies, DNS and flushing sockets.
@Snayberry - yea occasionally, maybe that's why it started happening? It's totally inconsistent though and I havent had any cancelled orders, etc.