There's only one official firmware version which supports FTP, 1.02.07.
Sorry, can't help you with your Filezilla problem, it worked first time for me (on an iMac, so not the same platform as you). A quick google suggests that some people who have experienced that problem found that it just "went away" - not very helpful really. The main other suggestion seems to be to change Filezilla from active to passive mode. As I say, I didn't have to do that, so I can't really comment.
ChertseyB did say he'd tried through Explorer as well and it just hung.
I think that if Filezilla is waiting for the welcome message then the initial connection has been established, which would seem to rule out a firewall issue. (Port 23 is the Telnet port. FTP uses port 21 to establish the session and port 20 for the file data.)