Permissions on USB disk connected to Time Capsule

Hi,

I'm trying to attach a 1TB USB hard drive to my Time Capsule, which I've managed to successfully do. However, whenever I write something to the USB drive, it's UNIX permissions get set to 777, and the owner and group get set to my user and group id. Even if I use something like "sudo rsync -aH" to copy the files, all of the existing permissions and ownerships get stripped and set to me. There are lots of "chown" error messages issued by rsyn. For instance:

rsync: chown "/Volumes/Snapshot-Softwolf/vanilla/Music/iTunes/iTunes Music" failed: Operation not permitted (1)

If I manually attempt to chown files on the USB drive, I get similar error messages. If I manually attempt to chmod files, I get silent failures. SImilarly, using Finder results in silent failures.

Is there any way to set up the USB drive to allow permission and ownership changes? A 3rd party solution would be acceptable provided it isn't too expensive.