I think there might be a bug when you quit while stat -la is being processed. Instead of just quitting ffxp displays the content of the directory in raw format in the status window.
Code:
250 CWD command successful.
PWD
257 "/BLA" is current directory.
STAT -la
QUIT
drwxrwxrwx 3 bla bla 83 Feb 16 2004 blablabla
drwxrwxrwx 3 bla bla 82 Feb 5 2004 blabla
...
I can reproduce the error every time. You just have to wait till the status window shows stat -la, then press quit. This is a slow server so stat -la takes 2-3 seconds.