Sometimes when I switch from external speakers to the (internal) TV-speakers the sound will not appear.

This is what happens. My TV is connected to a surround receiver. I watch TV with the receiver active for a while. Then I switch off the receiver. The TV screen shows the usual "TV-speakers are active" label. But no sound appears. It does not help to rise the volume or switch the TV off and on with the remote. The only way I have been able to get the sound back is to power the TV off and on with the power switch.

This does not happen often. I can't remember I have experienced this with older firmwares. I use firmware 0.140.32.0, it was installed yesterday. Anyone else experiencing the same problem?