I am running the same version, and had some sound issues at first. I finally got everything working by removing the comment in the startup script for secondlife that says "export LL_BAD_OPENAL_DRIVER=x".
Oh, I'm going to figure you already got this, but I missed it first time through. The stream settings in preferences are set to not allow streaming media with the initial load. I had to also check those boxes to allow it.
Check out the wiki, there are a lot of good suggestions in there too. http://wiki.secondlife.com/wiki/Linux_Viewer