Dear All: I am developing an USB audio driver with AVStream framework. The graphedit.exe is my test tool now. When I use the audio filter in "Audio Capture Source" category, I have meet a strange problem. (not from folder of WDM Streaming Capture Devices) First, audio sound can be played well in the filter. However, when the graph is stopped by me, I must return all pending StreamPointers in the (KSSTATE_RUN -> KSSTATE_PAUSE) state, otherwise the graphedit will be held by system. I have done 2 tests below: 1. When I return all pending pointers in the KSSTATE_STOP stage, I can't close the graphedit. The device need be removed, then graphedit can continue to be closed. 2. When I return all pending pointers in the (KSSTATE_RUN -> KSSTATE_PAUSE) stage, the graphedit can be normally closed. In some reasons, I must return remaining StreamPointers in KSSTATE_STOP stage. How can I do? I have referred some Microsoft's sample codes, they all return the remaining StreamPointers in KSSTATE_STOP state. Are there some mistakes in my driver setting? Best Regards, H.P.