Hi, I vaguely recall something similar happening to me, and it was caused by an error in my topology descriptors that was ignored by Windows 2000 but upset XP. I can't remember now what the error was, but it was something stupid like a mismatched node number or something. Once I corrected that everything was fine. Jeff Pages Innes Corporation Pty Ltd ----- Original Message ----- From: Harry Graham To: 'wdmaudiodev@xxxxxxxxxxxxx' Sent: Friday, June 06, 2003 5:08 AM Subject: [wdmaudiodev] AVStream mixer problems on XP Hi, I have created two AVStream filters, one for record, and the second for playback, each containing its' own mixer topology described by Node and Connections descriptors. SndVol32 displays the mixer lines and controls correctly on W2K (DirectX9), but fails to display correctly on XP (also DirectX9). For the record filter, all the relevant controls are displayed, but all the volume controls are disabled. For the playback filter, the result is pretty much nonsense. Lines are displayed that don't exist (CD and Unknown pin), and none of the analog lines (there are 4 of them) input to the summer are displayed. I have examined the sysaudio filters(KSCATEGORY_AUDIO_DEVICE) with KsStudio, and don't see any reason why SndVol32 fails to work on XP. The sysaudio filters are slightly different on XP, due to the addition of DRM, AEC, etc., but the analog lines are identical in both XP and W2K. Does anyone know what could cause XP to behave so differently from W2K? Thanks, Harry