trouble writing angstrom image to sd card.

Followed the getting started directions found at

downloaded the newest demo image from here:

and followed the directions at the bottom of the page.

I’m having the following problem writing the image:

eric@debian-eee1005pe:~/bone/img$ ls -l
total 145064
-rw-r–r-- 1 eric eric 148538884 Feb 22 00:38 Angstrom-Cloud9-IDE-eglibc-ipk-v2012.02-core-beaglebone-2012.02.14.img.xz
eric@debian-eee1005pe:~/bone/img$ ls -l /dev/sdb
brw-rw---- 1 root floppy 8, 16 Mar 17 15:05 /dev/sdb
eric@debian-eee1005pe:~/bone/img$ sudo xz -dkc Angstrom-Cloud9-IDE-eglibc-ipk-v2012.02-core-beaglebone-2012.02.14.img.xz >/dev/sdb
bash: /dev/sdb: No medium found

The card is in the slot, /dev/sdb shows up, (running debian on the host being used to write the card)… Now why is bash saying “no medium found”?