[Nottingham] Odd FTP problem

[stripes]

This problem just started today
Trying to ftp to muin.pair.com with a GUI client (gftp, kasablanca or
Igloo-FTP) fails
gftp gives 500 syntax error, unreconized command
server error 2 and disconnects
kasablanca gives 500 syntax error, unreconized command
stays connected show current working directy as / but can't get a
directory listing
Igloo-FTP connects complains it can't connect to a data socket,
eventually fails to get a directory listing and disconnects.