I ran into this once too...in the docs for AvStrMiniPinProcess, it states this: "The process dispatch is either made at the default IRQL = PASSIVE_LEVEL, or possibly at DISPATCH_LEVEL if the minidriver has specified KSPIN_FLAG_DISPATCH_LEVEL_PROCESSING in the relevant KSPIN_DESCRIPTOR_EX<http://technet.microsoft.com/es-es/query/ff563534>." So, I finally concluded that KSPIN_FLAG_DISPATCH_LEVEL_PROCESSING does not mean that the processing WILL happen at DISPATCH_LEVEL, just that it may. If you don't specify the flag, you're guaranteed that the processing will occur at PASSIVE_LEVEL. Jeff From: wdmaudiodev-bounce@xxxxxxxxxxxxx [mailto:wdmaudiodev-bounce@xxxxxxxxxxxxx] On Behalf Of Mike Horgan Sent: Monday, December 05, 2011 10:12 AM To: wdmaudiodev@xxxxxxxxxxxxx Subject: [wdmaudiodev] Specifying KSPIN_FLAG_DISPATCH_LEVEL_PROCESSING on audio render pin I am specifying this flag as one of many in the pin descriptor (KSPIN_DESCRIPTOR_EX) for an audio render pin. On invocations of my pin's Process() method, I call KeGetCurrentIrql() which returns PASSIVE_LEVEL (value of "0") which seems contrary to what the flag should've done.