I was able to work around the problem by placing the libasound2 and alsa-utils packages on hold in dselect. The dselect then upgraded the rest of my packages without choosing the liboss4 packages. I then allowed dselect to upgrade the libasound2 and alsa-utils and the problem was gone.
That time dselect did not insist on installing the liboss4 unwanted packages. I can't explain why dselect previously was choosing those unwanted packages. -- To UNSUBSCRIBE, email to debian-bugs-dist-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org