I ran into the same issue with linux mint debian edition, and a debian box running wheezy.
Following the instructions to wipe apt cache fixed the issue. Maybe add this tip to the FAQ or something.
I'm working on many updates now, and this is on the list of things to incorporate.
Also the registration process for this forum is really painful. I made a mistake in the email address and couldn't receive the confirmation email and was blocked from registering from the same computer, it also forced me to choose a less secure password than the one I wanted to use just for the sake of putting an uppercase letter and number in there.
So I restarted all over again from another machine and had to invent new username/email/password then the confirmation email would not arrive despite a couple resend.
This went on until I ran out of computers and had to resort to fiddle with cookies and found one email provider the registration would send email to.
I almost gave up around the 6th or 7th failed attempt at registering.
Actually, the registration system worked exactly as it should have. Your pattern of activities, including use throw-away email addresses, were entirely consistent with a spambot. And since I have very limited time to spend on this, I have zero tolerance for wasting that time dealing with spam. If I had truly aggressive registration settings, you probably would have managed to get your IP address banned.
While I certainly use throw-away email addresses at times myself, the registration for the forum is supposed to be a truly valid one (for example, to receive notification of responses to your posts). So there is a delay to try to avoid exactly what you did. I'm a little surprised you managed to register at all with that approach.