pulseaudio problems

I have just installed pulseaudio and pavucontrol on Xfce (debian GNU Linux
amd64 jessie 8 stable; GA-X79-UD3 with two GPUs) I managed in /etc/pulse/
default.pa to switch from default HDMI to analog output. However, in
pavucontrol the output device is blinking, i.e., there is a continuous
switch betweem heahphone and line out analog.

I noticed on Internet that this is a bug.

Thanks for advice

(with the same OS on a desktop without GPUs/CUDA there is no such problem,
actually sound workks nicely on the same couple of speahers)

francesco pietra