This thread is an example of many discussions I have seen on the topic http://forums.oztivo.net/showthread.php?t=1875
Supposedly it will be a feature you can pay extra for in the future. It also sounds like a nice puzzle for us to solve.
I wonder how its done? Perhaps /dev/hdb* is missing and could be enabled with mknod? Thats how tivo prevented more than 16 partitions per drive http://www.dealdatabase.com/forum/sh...ad.php?t=60546