Just something to try to get your audio to work.
Try hard resetting your Slingbox. This will force the Slingbox to look at the analog audio ports again.
If you do not know how to perform a hard reset, check out the hard reset article below:
After the reset is perform, please wait until the network light comes back on and go to setup on slingbox.com to re-setup your Slingbox.
Hope this helps!!!
Sling Media Moderation Team