[X4U] Fwd: MacBook Pro Audio Crisis - please help!

[Steve Talkowski]

A fellow Mac user on a non-computer related mailing list is having  
the following problem.  Nothing that I've ever encountered before on  
my MacBook Pro.  Any ideas I can send his way?

-Steve

> I know there are some Mac wizards on the list, so I'm hoping  
> someone can
> help me with a bizarre development: My MacBook Pro is suddenly  
> refusing to
> make any noise.  When I try to turn the volume up or down using the  
> keys in
> the top row of the keyboard, I get that "forbidden"/"Ghostbusters"  
> symbol
> (you know, the circle with the line through it).  What is going on,  
> and how
> can I fix this???
>
> (I've already shut down and restarted the computer--it didn't work.)