Man, I'm gonna be annoyed if 3TB works. I got multiple confirmations from Dish that 2TB is the max since I didn't want to waste my time buying something that I couldn't fully utilize. But I would have bought a 4TB if I knew it would work. I just don't have any other use for it if it doesn't.
My 2TB MyBook Essential showed around 1858 (give or take; I don't remember exactly) so a 3TB should show around 2780-2790 freshly formatted.
kpip99, what did the Freespace: field show on the external device when you first formatted it?
Edit: FWIW, my 2tb drive is split into multiple partitions. Volume 21 and 22 are 500 gig EXT3 partitions with the remainder raw/unpartitioned. I assume it creates and formats the first two partitions during the initial setup and the rest as it's needed. It's possible that, since it creates partitions in such "small" chunks, it may not be able to create enough partitions to utilize 3 and 4tb drives.