http://patrikluca.blogspot.com/2008/05/restore-subsite-parent-web-does

I had exported a subsite having over 50 subsites beneath it using the stsadm -o export command. Upon importing the hence created backup file using the stsadm -o import command on another server, a fatal error occurs. The error logged is: FatalError: The file cannot be imported because its parent web <URL name of the exported subsite> does not exist.