Nodes? After a half dozen tries, I successfull transplanted the BTC chain, but the Credits chain isn't coming.
Have you tried:
a) checking the log via Help > Credits debug window > Information > Debug log file > Open. If there is output coming there the Credits blockchain is probably downloading.
b) Restarting the client. I've seen situations where the Credits blocks doesn't start to download until a restart, probably due to timeout of the Credit nodes waiting for the Bitcoin blockchain download.
You could also check Help > Credits Debug Window > Peers and see if you are connected to peers.