ftp (proftpd) 421 Login Timeout

I am having a problem with my Direct Admin FTP. My users (nor I, the admin) can log in to the ftp server. When attempting to FTP, we get:

connecting to xxx.xxx.xxx.xxx:21
Connected to xxx.xxx.xxx.xxx port 21
421 Login Timeout (120 seconds): closing control connection.
! Connection failed xxx.xxx.xxx.xxx

The timeout error comes instantly, it does not wait 120 seconds. If I restart the proftpd service, it works again. ...but in a few minutes stops and the timeout error comes back. ...again, this is causing severe trouble since it is happening to all my customers and has only been happening in the last 15 days (previously it has worked great). The only thing that could have caused it (on the admin end) is that I created a user and gave them ssh access to their account (that is the first user I have given ssh access to).

I checked all the proftp logs and everything is fine, no signs of errors anywhere. Top shows proftpd as being fine and even the proftpd status is fine. ...so I am stumped and need help. Some of my customers are irate. ...I am not, but do need some help figuring this out. ...and I am afraid it is one of those not so straight forward, nebulous errors.

Thanks a ton!!!!!!!!!!!
A DirectAdmin fan!!!
Higinio

I'm haveing the same problem. Anyone?

I know you checked the proftpd logs but are there any messages in logged in /var/log/messages that might give a clue to what is causing it to malfunction? What do the proftpd logs (and/or messages) say when a user attempts to conect but timeouts?

What operating system and version are you running?

I've sent you a PM