IO error encountered -- skipping file deletion

[Master Abi]

Hi list,

I have a Windows server backing up to a Linux server that continuously 
gets 'IO error encountered -- skipping file deletion' in the receiver 
log file. Could someone enlighten me where and what this error is 
referring to. I have tried various options, like using --delete or 
--delete-during. Still the same problem.

Is it on the sender or receiver side, or a timeout encountered somewhere.

I am using 2.6.8.

Client: Windows with cwrsync
rsync -aqrz --delete-during --password-file=<..> "/cygdrive/c/........" 
<Auth User>@host::acs

Server:
[acs]
path = /var/rbackup/acs
read only = false
list = false
uid = ftpuser
gid = users
transfer logging = yes
log format = [%a] %o %m (%u) %f %l
auth users = <Auth User>
secrets file = /etc/rsyncd.secrets
incoming chmod = ugo+rwx

Thanks
Master