fabiolcati wrote:What is your OS?

Windows 7 64-bit -- which reminds me that I have a OSX and I can try the file there... more in a bit.

fabiolcati wrote:Notion build?

3.1.281

fabiolcati wrote:I work with GPO almost daily but never noticed something like this...

Strangest thing ... I'm having sort-of the same problem. When you don't have any sound, if you open the mixer during the "silent" playback, are the meters active, i.e., is there activity? Also, if you File -> Close and then open a new project (or one known to play), is there sound? I'm try...