With bpmdj 2.6, /usr/share/bpmdj/sequences is installed root:root, 600. Since it should be sample files that are shared across all users, that should be 644. As it is, non-root users can't see the files.
Can you check if 2.7 version is fixed?
I'm getting bitten by bug 151656 (just filed) so I can't tell yet... ;(
This one had been removed some months ago.