My audio has always worked perfectly on this hardware and 12.04. Yesterday I received an update, including a kernel update. Today the sound is periodically stuffed. In youtube, mkv files via VLC and embedded audio in web pages (memrise.com) the sound can become stuttery, sped up or stopped mid play-back.

Where can I go to find if this is a known problem, or report it if it is not? Also, can I find a log that will tell me what packages were updated on my machine yesterday?