Greetings everyone,
Regarding the issue of having the sound mute randomly, and in TH IT's case, unmute, please get in touch with the Surface Technical Support to exchange the Touch / Type Cover. We're still investigating the issue, however it appears that the cover may be the
issue.
You can do the exchange yourself here: http://myservice.surface.com or by contacting our Technical support team here:
http://www.microsoft.com/surface/support/contact-us/.
Please let us know if the exchanged Touch Cover / Type Cover resolves the issue for you.
Thanks for this post. However, it would seem that this problem may not be related to the touch cover or there may be multiple causes based on the replies here.
Mine is a Surface RT 32GB. I just got it brand new a week ago. I don't know how to find the type cover model number however.
I found another thread where the guy disabled the HID device that allows the volume and play/pause keyboard controls to work.
You do it in Computer Management -> Device Manager -> Human Interface Devices -> HID-compliant consumer control device. Double-click the SECOND one to view its properties, pick the Driver tab and then click disable and say yes to the resulting dialog box.
It will simply disable the four keys for Volume and Play/Pause.
It's working for me so far. I'll keep it like this until an official solid fix is found.