Chromium sound stopped working / all other sound OK

[aneurysm1985]

Hi guys, I am running running Linux Mint 13 (64-bit, Cinnamon) and Chromium 18.0.1025.151 (the current release supported through Update Manager).

Sound was working OK with Chromium until last week, until it suddenly stopped. I can still hear sound from other apps (e.g. VLC, Exaile, Firefox), but when I try to play audio/video files through websites in Chromium (e.g. YouTube, Rdio), I get no sound.

Can anyone diagnose what may have happened. If I recall the chronology correctly, I may have installed the extra Mint codecs in my previous session before the problem started (I had been running Mint 13 for a week before clicking on this option to download the codecs). Could this installation have broken something?

[aneurysm1985]

I tried Opera and am getting no sound in that browser either. Firefox is still working fine. Could this be a plugin/driver/codec issue?

Any suggestions?