rsync - Dec 2007 - error in rsync protocol data stream

Help. This one's defeated me so far. I'm tring to push files from from a
local Ubuntu 6.06 server to a remote Ubuntu 6.06 server using rsync (v 
2.6.6 installed on both via apt-get). Every time I get the same eg:

building file list ...
4 files to consider
./
Demo1.plt
       63459 100%    7.32MB/s    0:00:00  (1, 50.0% of 4)
Test.plt
        1280 100%  208.33kB/s    0:00:00  (2, 75.0% of 4)
USA_wp.txt
       39032 100%    2.66MB/s    0:00:00  (3, 100.0% of 4)

...... very long pause ....... then:
Read from remote host <remote.ip.address>: Connection timed out
rsync: connection unexpectedly closed (84 bytes received so far) [sender]
rsync error: error in rsync protocol data stream (code 12) at io.c(434)

When there are new sub-directories involved, they get created OK on the 
remote server (proving we get a vaild connection), but no files get 
transfered. So I tried synch'ing just a single file, and found that a 
text file of a few kilobytes transferred OK, but once it reached a few 
tens of kilobytes, it no longer transferred and I got the behaviour above.

I did have denyhosts running, which caused problems by adding my IP 
address to hosts.deny, but I removed it and killed the process but it 
makes no difference.

There is a reference to this behaviour in the rsync FAQ (the transfer 
fails to finish), but I'm afraid I can't follow the information 
supplied. Presumably it *is* possible to rsync between 2 Ubuntu Dapper 
servers?

Richard Jones wrote:
> Help. This one's defeated me so far. I'm tring to push files from
from a
> local Ubuntu 6.06 server to a remote Ubuntu 6.06 server using rsync (v 
> 2.6.6 installed on both via apt-get). Every time I get the same eg:
Not much help so far :-( I've managed to isolate the problem somewhat, 
but am still baffled. I have 4 more-or-less identical setups which I 
have experimented with pushing files between. Two remote VPS servers can 
transfer files in either direction OK, and both can push files to my 
local server OK, but my local server cannot transfer files to either 
remote server. But it can transfer files to a local VMware server 
located on the same network.

 From this I conclude there is something interfering with file transfers 
from my local network to the outside - a firewall perhaps? The rsync 
message can get across the divide, as it generates a remote response, 
but no files ever get transferred.

There is nothing obvious on the local server IP tables, but the router 
has some rules for port forwarding inbound port 22 to the local server. 
I don't see why it should prevent outbound rsync file transfer, since it 
doesn't block outbound mail, but is there something in the router config 
I should examine more closely?