[Nottingham] query on rsync

[godfrey]

Hi,

I wonder if anyone can help with a little difficulty I have concerning rsync 
between two machines? It is all to do with unattended backups. 

Let me call the machines, A and B, and the usernames userA and userB.

Now, userA uses ssh-keygen and creates id-dsa and id-dsa.pub. For ease of 
confusion, I will call these two files idA and pubA. Similarly, userB creates 
idB and pubB.

userA connects to B with ssh, and saves the key in known_hosts as does userB.
The two public keys (pubA and pubB) are transferred and saved in 
authorized_keys on each other's machines.

At this point userA can use ssh to give commands on machine B, and userB can 
do the same on machine A. Also, userA and userB can use rsync directly to 
transfer files between the machines.

Problem is, userA connects to machine B using ssh, then issues command to run 
rsync to transfer a file, and it fails "Host authentication failed"

Anyone any ideas?

regards,

Godfrey