Good morning Victor,
I came across this while trying to Google a solution to the same issue.
It would be superb, and much appreciated if you were able to post a snapshot build with this workaround in place.
Unrelated: While the forum, and it's registration is available via HTTPS, the captcha script on that page is not, so will not display on modern browsers; silently preventing registration. It may be helpful to update the HREF for the captcha Javascript to use a protocol relative URL ("//<url>") for that resource so it Just Works(tm) regardless of HTTP or HTTPS. 
Best,
Mike.