Sound Problem

[flyingmint]

I am using Mint 12 Lisa with Cinnamon Desktop and have an strange problem with the sound, when listening to music the volume is going automaticly on mute while playing with normal volume. Everytime when this happens i must reboot the computer and that is verry annoying and strange it seems there is an problem with an device or application i use normally Totem and in some cases VLC for playing music or videos.

I have the following sound device:

00:05.0 Audio device: nVidia Corporation MCP61 High Definition Audio (rev a2)

Can someone tell me why the device is automaticly going on mute and an restart is required.