Onkyo receiver won't lower volume

Hi there,

I've had my Onkyo TX-NR818 for 2 years now and everything has worked fine. Suddenly, I am finding that it will not adjust volume for some inputs.

For example, when I turn on cable, everything works just fine. However, DVD and PC inputs will not adjust volume down past 50, however will happily amplify it above 50. I've noticed that when I switch to DVD from Cable the volume will remain at previous setting for a few seconds and then suddenly jump up.

I've tried connecting Cable box to DVD input, and volume can be adjusted up and down.

I am very puzzled by this. Has anyone seen this before?

Thanks in advance,

jdw