[strongSwan] Phase 2: our client ID returned doesn't match my proposal betweetn two StrongSwans

[Jakob Curdes]

.. we have one  strongSwan U4.3.5 and on the second box  a  U5.1.2; when 
initiating a connection using IP addresses as IDs I get

"our client ID returned doesn't match my proposal" in Phase 2 although 
the IPs are the correct ones (or Phase 1 would probably fail...)
If I switch to hostnames as ID's, I get the same result. The connection 
is initiated from the U4.3.5 box.

Any ideas?

Regards,
Jakob Curdes