I’m developing a “virtual” sound card driver using the msvad examples as a starting point. I built and am running them on a 32 bit Win 7 machine. To test the virtual driver I set it as the default card and start playback to it. I then have a simple app that calls the loopback capture interface on that driver and then passes that data for playback by the “real” driver using WASAPI calls. This works fine when a single audio application is running. But if I start a second audio application and begin playback directly to the real sound card, probably 95% of the time the playback functions correctly to both cards. But 5% of the time I’m crashing to the blue screen of death. However when I test this same scenerio using any of the several commerically available virtual audio drivers, (like the one from virtualaudiostreaming.net) I never get a crash. I’ve tried all the various driver versions in the msvad folder and all of them are crashing around 5% of the time. Does anyone know if there is anything in particular about the implementation of the msvad driver examples that would make them prone to crash in this scenerio? I’m just getting started in driver development and I haven’t had to do any debugging yet, how difficult would it be for me to run this test in a debug environment so I could see what is happening? Thanks, Fred