Problem with rsync over ssh

[Peter P GMX]

Hello, I have the following problem:

On our internet host I have running rsync-static-2.5.7-1 (I have to use 
the static one as our web hoster had installed a limited Suse 9.1 
vserver system)
On our local server which I would like to rsync I have running rsync  
version 2.6.8  protocol version 29.

I can remotely execute applications throungh ssh without a password. But 
rsync won't run.

On the server's side rsync is running as a deamon. On both servers I 
have a user copy50 who is allowed to execute /usr/bin/rsync-static 
(which is linked to /usr/bin/rsync).

I get "rsync error: unexplained error (code 255) at io.c(463) 
[sender=2.6.8]" on the clients side.
It may have to do with the diffente rsync versions but I have no other 
solution as our web hoster didn't provide neither an updated rsync 
version nor the kernel headers for this kind of Suse Linux vserver)

I've googled around and found a number of similar problems but all 
solutions there did't fix my problem.

Any clue?
Best regards
Peter

Here's our rsyncd.conf
===========================================
read only = false
use chroot = false
transfer logging = yes
log file = /var/log/rsyncd.log
pid file = /var/run/rsyncd.pid
hosts allow = 217.24.xx.xxx/255.255.255.248
[backup]
    path = /home/copy50/backup
    read only = false
    list = false

I run the following command on the clients's side as user copy50
===========================================
rsync -avzP --exclude-from rsyncexclude -e "ssh -l copy50" 
/home/copy50/backup 62.75.xx.xxx:/home/copy50/backup

This is the output
===========================================

$ ./rsync50.sh

building file list ...

4 files to consider

rsync: connection unexpectedly closed (8 bytes received so far) [sender]

rsync error: unexplained error (code 255) at io.c(463) [sender=2.6.8]


The ssh logs says:
===========================================

*Dec 11 19:59:44 vsxxxxxxx sshd[19558]: debug1: monitor_child_preauth: 
copy50 has been authenticated by privileged process*

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: PAM: reinitializing 
credentials

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: permanently_set_uid: 
65007/100

*Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: Entering interactive 
session for SSH2.*

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: server_init_dispatch_20

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: 
server_input_channel_open: ctype session rchan 0 win 131072 max 32768

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: input_session_request

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: channel 0: new 
[server-session]

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_new: init

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_new: session 0

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_open: channel 0

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_open: session 0: 
link with channel 0

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: 
server_input_channel_open: confirm session

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: server_input_channel_req: 
channel 0 request exec reply 0

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_by_channel: 
session 0 channel 0

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: 
session_input_channel_req: session 0 req exec

*Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: Received SIGCHLD.*

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_by_pid: pid 19561

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_exit_message: 
session 0 channel 0 pid 19561

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_exit_message: 
release channel 0

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: session_close: session 0 
pid 19561

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: channel 0: free: 
server-session, nchannels 1

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: Connection closed by 217.24.xx.xxx

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: do_cleanup

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: PAM: cleanup

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: Closing connection to 217.24.xx.xxx

Dec 11 19:59:44 vsxxxxxxx sshd[19560]: debug1: PAM: cleanup


More detailed around *Received SIGCHLD *with debug level 3:
===========================================

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: server_input_channel_open: 
ctype session rchan 0 win 131072 max 32768

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: input_session_request

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: channel 0: new 
[server-session]

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: session_new: init

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: session_new: session 0

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: session_open: channel 0

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: session_open: session 0: 
link with channel 0

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: server_input_channel_open: 
confirm session

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: server_input_channel_req: 
channel 0 request exec reply 0

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: session_by_channel: 
session 0 channel 0

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: session_input_channel_req: 
session 0 req exec

Dec 11 20:11:34 vsxxxxxxx sshd[3445]: debug3: channel 0: close_fds r -1 
w -1 e -1 c -1

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug2: fd 8 setting O_NONBLOCK

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug3: fd 8 is O_NONBLOCK

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug2: fd 10 setting O_NONBLOCK

*Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug1: Received SIGCHLD.*

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug2: channel 0: read<=0 rfd 8 
len -1

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug2: channel 0: read failed

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug2: channel 0: close_read

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug2: channel 0: input open -> drain

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug2: channel 0: ibuf_empty 
delayed efd 10/(0)

Dec 11 20:11:34 vsxxxxxxx sshd[3444]: debug2: notify_done: reading