Currently Avatars are stored as a full URL since they can be local default ones, uploaded or linked to another server. Initially I was going to automatically change the URL to the new one, but some sites have avatars in locations that won't actually get moved during the import. The only real way to fix this would be to move the avatars after the import and then do a MySQL regex to replace the old avatar directory with the new one.
I'd need to lookup the actual command, just woke up and brain isn't quite working yet
