After upgrading to Kubuntu 13.04 (Raring Ringtail), Amazon Prime video would no longer play back in Chrome or Firefox.
I tried all the usual fixes: Install hal, libhal, make sure I had the latest flash player, etc. but nothing seemed to work.
As it turns out hal was not working out of the box.
sudo /usr/sbin/hald --daemon=no --verbose=yes
13:02:43.542 [I] hald.c:672: hal 0.5.14
13:02:43.542 [I] hald.c:673: using child timeout 250s
13:02:43.542 [I] hald.c:741: Will not daemonize