I seem to be getting no sound when playing back clips in the VSE under the 2.54 beta. 2.49b lets me hear sound fine, but loading the same clips into 2.54 and hitting Alt-A, nothing but silence.
I’ve tried fiddling with the playback options (I noticed ‘mute sounds’ was checked, but unchecking it didn’t help). Also, I checked Windows’ volume level mixer - Blender didn’t have an entry there alongside iTunes, but then again, neither did 2.49.
Is this a known issue? Searches haven’t seemed to turn up anything. I’m running Windows 7, 64-bit. I’m going to try it on Ubuntu 10.04 next, though my searches have brought up a lot more about bugs related to audio in Ubuntu, so my hopes aren’t high :P.
I am having the exact same problem. I am also using Blender 2.54 on Win7 64.
EDIT: I went into User Preferences, System, and clicked the “SDL” button. Now sound works.