I cant work this out!

Thanks Kevin,

I connected vccs in the top level, replacing the switches and it worked - lower volume audio on channel1 as expected

http://farm8.staticflickr.com/7015/6754948481_5471b4c4cd.jpg

As soon as i connect the switches i get nothing from the audio

http://farm8.staticflickr.com/7003/6754963697_ac5eaf3c83.jpg

I looked in the RTL viewer, technology map viewer post mapping and post fitting in Quartus and the switches are connected right down to the lowest level.

I'm not sure what you mean by timing path from input pins to output pins?

Is there something totally obvious i am missing here?