No Sound on Windows 7 host after host sleep

[Gary]

Version info: Host: Windows 7 64-bit VM: Windows XP SP3 32-bit VirtualBox: 3.2.6 Guest Additions: 3.2.6

I have two soundcards in this VM - the virtual AC'97 card, and a physical USB sound card. Sound works coming through the USB card, but not the AC'97 card. None of the volume controls are muted, all turned up to full. Sound works normally on the host.

Sounds has previously worked on this VM running on a different Win7 PC.

I found that VBox.log is full of these messages (full log attached):

00:22:50.180 DSound: Reason: The buffer memory has been lost and must be restored

I have tried:

• Increase the RAM available to the guest from 1GB to 1.5GB, but it didn't help - I doubt that's the problem, VirtualBox.exe is only using ~55MB.
• Installing the drivers from Realtek.com
• Removing the USB sound card and rebooting
• Removing all sound card drivers, reboot, allowing the guest to reinstall all drivers

There doesn't appear to be any conflicts between the two sound cards.

Discussion here: ​http://forums.virtualbox.org/viewtopic.php?f=6&t=32982

[Gary]

VBox log file

[Technologov]

How many sound cards do you have on your physical computer (host) ?

-Technologov

[Gary]

I'm not sure how, but rebooting the guest and host seems to have fixed the problem - I now get sound from both the virtual AC'97 and the USB sound card. I guess this ticket can be closed.

[Gary]

Further investigation - seems the issue is caused by putting the host to sleep. After waking, the virtual AC'97 doesn't work on the guest. So, this is actually a repeatable bug.