Good news,
I reported to Norton that I'd been visiting the Rx site for years and that it's not a "malicious site with malware" (that was the screenshot I was trying to post on the weekend).
Today I received this email from them:
"Dear Customer,
This is an important message from Norton Safe Web. We have recently re-evaluated the contents of http://www.therxforum.com/memberlist.php.
The website rating is successfully changed.
For details about this site report, you can go to: http://safeweb.norton.com/report/show_mobile?url=http://www.therxforum.com/memberlist.php
Thank You!
Norton Safe Web"