I have been having the same trouble today, trying to activate html editor. I get the same error.
It hangs dreamweaver for a couple minutes, then comes back with that error.
I think they must be having problems, as I couldnt get the forums to load, or the site to load for a while. I even tried through a couple proxies, and still no luck.
I can get in to webassist.com now, and obviously the forums, but I still cannot activate.
There really needs to be an offline method of registration, in case something like this happens.