Recording and Stero mix

Hi

When I use varoius different recorders to record
streaming radio I have to set the master volume version
5.1 to recording options and click the "Stero mix" box.
(That way I get a signal into the recorder)

ALl is fine, but after a bit the box unchecks itself and
I get no more signal.

This unchecking may be to do with when I use other
applications - I am not sure if its consistent.

It is annoying to put it mildly!!!

ANy ideas

thanks in advance