Are you using HDMI to send the audio or the audio-in port?
Also, if you're connecting a PC, make sure you edit the name in the Setup Menu from "----" to "PC".
One last tip - check to see that your drivers are up to date.
I'm having a bit trouble when I'm trying to connect my PC to the TV.
I have a Nvidia GeForce 9400 GT and creative SB0460 X-Fi sound card, and would like to use the TV as a default speakers but no matter what I do it doesn't seem to work..
I would really appreciate your help!