I'm having an interesting issue pop up with our audio driver we are developing. I've noticed that sometimes after the system returns from S3 or S4 the driver is disabled and then enabled. This is happening on Vista 32-bit/64-bit and happens with hibernation or sleep. This does not happen every time and most times the system returns without disabling and then enabling the driver however when stressing the driver for WHQL we've noticed this issue come up within a couple of hours every time we run the common scenario sleep test. Is this expected behavior of Vista or should I look at my driver design for the cause of this issue. Thanks for any help.