After more investigation it looks like this is caused by flaky hardware on my side.
This bug report can be closed. If in the unlikely event that it's not caused by my hardware, I will open a new / reopen the report. Thanks for your time, and apologies for wasting it. -- Tor -- Fails to play at random times https://launchpad.net/bugs/58983 -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs