Due to prodding from eye208 and the real issue that a lot of people are having problems getting Second Life to work with PulseAudio, I looked into it.

It seems that the people who wrote the audio interface for the Linux edition made a mistake in their code:

http://jira.secondlife.com/browse/VWR-5708

The Second Life devs have been made aware of this so I imagine a fix is in the works for some future release or a patch.

I did some more digging around and found a tentative fix for the current release here in this thread:

http://vboards.stratics.com/showthread.php?p=836114

If someone who uses Second Life could try it out and let us know how it works, or if someone knows if the devs have already patched it, it would be appreciated and you will get a big thank you!!