This has nothing to do with the usual forum user login, but is an additional username/password request that you will see as a little pop-up window created by your web browser -- just enter "guest" for both username and password, and you'll be fine.
I hate to add such measures, but this "attack" made the whole web server unusable for several days, so I had to do something against it. So far, this seems to be sufficient to keep the scrapers away. As soon as AIs will read the content of web pages that ask for a password, I will have to do something different to keep them away.
Sorry for the inconvenience, and have a lot of fun with the R'n'D forum nevertheless!
