There is a known issue we've been waiting about five months for Parallels to fix: if you migrate a site in 10.4 and it contains subdomains, the subdomains will be stuck on the ip address from the old server and not the new site IP. Here's a past thread on it that never got any Parallels attention: http://forum.parallels.com/showthread.php?p=621268#post621268 After the migration, any change you try to make to the subdomains results in the error "Failed to updated ip. Can't set to addon domain ip different from webspace ip." The fix is to hand edit the IpAddressesCollections table in the database and set the subdomain id's, which are a pain to figure out, and set the ip id numbers to the correct values, then regenerate the config for all the affected subdomains. Well now we have a second problem. Even if you do the above fix, if you enable IPv6 for the primary domain, the error comes back when you try to make any changes to subdomains. I have not been able to figure out any working combination of values in the IpAddressesCollections table that will make the error go away. The only workaround I can find is turn off ipv6, make the changes you need to the subdomains, then turn it back on. We need a fix for both of these issues Parallels. If you can at least tell me what to do to fix the ipv6 issue I'd appreciate it since at least I would then be able to work around the bugs in both cases. And no, I don't want to upgrade to Plesk 11 to fix it.