[sismed]

I had the same rpc problem in my logs.
I was trying to import mailboxes from lotus domino.
The problem was that if your zimbra server is at "zimbra.domain.com" and the mail domain that you want to use is "zimbra.com" it won't work.
It solves adding to the "hosts" filename a fake resolution like
"ip of zimbra.domain.com" "name zimbra.com"
I will try to open a bug about this problem

thanks again