Hi, I have implemented a virtual audio driver, based on the MSVAD simple example in the SDK. Everything seems to be working well, unless I go into a sleep state while streaming audio in any player other than WMP. In this case, when the computer resumes from sleep, the audio panel volume control will be frozen, and the entire driver appears to be stalled. The computer has to be restarted in order to fix this problem. After looking into the problem more, I'm seeing that the computer is going to sleep without first placing the stream into a pause or stop state. This causes the stream to resume from sleep in a running state. The reason WMP doesn't cause this issue is because it proactively pauses and stops the stream. Furthermore, in this bad state, the computer does attempt to pause the stream immediately after we wake up. For example, a good sleep transition will look like this: RUNNING -> PAUSE -> [SLEEP/WAKE] -> PAUSE -> RUNNING; while a bad sleep will look like this: RUNNING -> [SLEEP/WAKE] -> RUNNING -> PAUSE (from before the sleep) -> FROZEN. It seems like either the portcls or the miniport are preventing the OS from setting the proper stream state. I've tried everything I can think of to resolve this issue, with no luck. If anyone could lend me some advice, I'd greatly appreciate it. Thanks, David