We have recently migrated multiple servers from Plesk 9.5.4 to new servers running Plesk 10.4.4. The vhost.conf files for domains that had those in their conf folder were migrated, but vhost_ssl.conf files were not, which required us to manually migrate these files. This sounds like a bug in the Plesk Migration Manager.
The latest migration we did was from a server running Plesk 9.5.4 (latest current micro update) on CentOS 4 to a server running Plesk 10.4.4 MU#20 on CentOS 6.
The latest migration we did was from a server running Plesk 9.5.4 (latest current micro update) on CentOS 4 to a server running Plesk 10.4.4 MU#20 on CentOS 6.