We have a debian testing server. When I am trying to access the server with scp it doesn't work the first time - the client says, that the remote host closed the connection. When i try the same action again - it works. Then the calls work for some minutes - but after (I think) 5 to 10 minutes it stops working again and the "first call" doesn't work again. After that it works again for 5 to 10 minutes.
Checking the syslog I can't see anything (we had the problem that the syslog is HUP - but we are working on this). Checking the auth.log it seems that the call is not getting through (I just see successful attempts in it).
Do you have any ideas on what could be wrong ?