No sound recorded in stereo mix

My computer runs Windows Vista +the support packs.

I have been successfully recording from internet radio for months, using version beta 1, but overnight it stopped working. When I Click ‘record’, no sound is recorded. I have now downloaded and installed the version 2.0.2 but the same thing happens.

I visited the FAQ and made sure that all the advice has been carried out, but still no luck.

The problem is … one day it worked and the next it didn’t. I don’t know why … any advice ?

What do you have set as the recording input in the Device Toolbar? http://manual.audacityteam.org/man/Device_Toolbar
Do you use any other audio programs? In particular, do you use any other audio recording programs or “voip” programs (such as Skype).
Have you recently installed any new programs?
Is Windows Update enabled?
Does anyone else have access to the computer?