This is probably a hangover from the extreme methods used to counter several DDOS attacks last week: your IP has been flagged as a bad agent.
You need to ask the admins directly to fix it - only they can access the blacklist.
Post your message here:
Bugs and Suggestions[
^] and they will fix it for you.
Be aware that it may take a few hours: they are all in Canada so it's the middle of the night there!