Some of the config you used appears to be outdated, or incorrect. Since I have seen other sites with the same blocks of config, I must assume outdated.

Great tutorial, but you might want to specify versions that it will [not] work with.

Just in case it might help someone, here is my dumptype, and tapetype definitions.

CentOS5:

 define dumptype custom-tar {
 program "GNUTAR"
 comment "root partitions dumped with custom compression"
 compress server custom
 server_custom_compress "/bin/gzip"
 priority low
}

define tapetype HARDDISK {
 length 100000 mbytes
}

But as far as setting it up, awsome tutorial, much appreciated!