I have a similar problem with Volumio 1.2.
My setup is :
Raspberry Pi model B
SD Card 4GB
When I add my NAS in Volumio (SMB), everything works perfectly.
However, after some minutes of use, the music stops and the web interface is down.
The SSH access is still operational but seems to be slow.
Airplay also work at this time.
If I run the following CLI, Airplay do not work anymore :
sudo apt-get update
The only way to make the Volumio Web Interface working again is to flash again the SD card with a new Volumio installation…
I also tried to add the NAS share manually (like on this page : volumio-update-t790.html). It works but the web interface is still down after some minutes of use.
If I do not add any share on Volumio, Volumio seems to be stable.