"Port 21 Open" messages may be incorrect FYI, I think 'Port 21 is open' is a bug on this system. I ran the Java applet portscanner on this system, and it claimed everything was okay except that Port 21 was open. Well, I checked, and it shouldn't have been open - so I ssh'd into a separate system and double-checked.
I physically ran an nmap port scan against my system from a completely separate system elsewhere on the internet, and it only listed the only port I had open, port 80. (This is intentional.) Port 21 was closed (ran it with -p21 just to be sure), as it should have been, *not* open.
Argh! As such, if you're worried about port 21 being open despite what your firewall software claims, well, it probably isn't open.
Worst case, try an independent source, like »www.grc.com/x/ne.dll?bh0bkyd2. (Yes, that's a freaky URL, but that's where they keep ShieldsUp. Go figure.)