Was having this same problem, but I was just now able to log in. I tried your fix, and I still had no luck. I thought for sure I have verified my email address, but I went to my inbox just to make sure. I search for any mail containing “guild wars 2” and I saw an email asking me to verify, but no verification conformation, so I followed the link in the email requesting verification, logged in. Site said Verification Success. So I immediately went to the forum, logged in, accepted user agreement, BAM! Success.
Long story short if you are experiencing this problem, search your inbox for the verification email, and try verifying your email address (again if you think you already did).