diff --git a/reactos/drivers/ksfilter/ks/irp.c b/reactos/drivers/ksfilter/ks/irp.c
index 21a6dd8c62b..5a1fb5b2209 100644
--- a/reactos/drivers/ksfilter/ks/irp.c
+++ b/reactos/drivers/ksfilter/ks/irp.c
@@ -888,6 +888,10 @@ ProbeMdl:
             goto ProbeMdl;
     }
 
+#if 0
+    // HACK for MS PORTCLS
+	HeaderSize = Length;
+#endif
     /* probe user mode buffers */
     if (Length && ( (!HeaderSize) || (Length % HeaderSize == 0) || ((ProbeFlags & KSPROBE_ALLOWFORMATCHANGE) && (Length == sizeof(KSSTREAM_HEADER))) ) )
     {
@@ -1940,7 +1944,7 @@ KsSetMajorFunctionHandler(
     IN  ULONG MajorFunction)
 {
     DPRINT("KsSetMajorFunctionHandler Function %x\n", MajorFunction);
-#if 0
+#if 1
     // HACK
     // for MS PORTCLS
     //
diff --git a/reactos/drivers/wdm/audio/legacy/wdmaud/mixer.c b/reactos/drivers/wdm/audio/legacy/wdmaud/mixer.c
index 4229290a6d0..df9cad510fa 100644
--- a/reactos/drivers/wdm/audio/legacy/wdmaud/mixer.c
+++ b/reactos/drivers/wdm/audio/legacy/wdmaud/mixer.c
@@ -1888,6 +1888,12 @@ WdmAudGetLineInfo(
         }
 
         MixerLineSrc = GetSourceMixerLineByComponentType(&DeviceExtension->MixerInfo[(ULONG_PTR)DeviceInfo->hDevice], DeviceInfo->u.MixLine.dwComponentType);
+        if (!MixerLineSrc)
+        {
+            DPRINT1("Failed to find component type %x\n", DeviceInfo->u.MixLine.dwComponentType);
+            return SetIrpIoStatus(Irp, STATUS_UNSUCCESSFUL, 0);
+        }
+
         ASSERT(MixerLineSrc);
 
         /* copy cached data */
diff --git a/reactos/drivers/wdm/audio/sysaudio/control.c b/reactos/drivers/wdm/audio/sysaudio/control.c
index 190641aa8c9..b096d4d9dcc 100644
--- a/reactos/drivers/wdm/audio/sysaudio/control.c
+++ b/reactos/drivers/wdm/audio/sysaudio/control.c
@@ -208,7 +208,7 @@ ComputeCompatibleFormat(
 
     MultipleItem = (PKSMULTIPLE_ITEM)(PinRequest + 1);
     MultipleItem->Count = 1;
-    MultipleItem->Size = sizeof(KSMULTIPLE_ITEM) + ClientFormat->DataFormat.FormatSize;
+    MultipleItem->Size = ClientFormat->DataFormat.FormatSize;
 
     RtlMoveMemory(MultipleItem + 1, ClientFormat, ClientFormat->DataFormat.FormatSize);
     /* Query the miniport data intersection handler */
@@ -229,7 +229,7 @@ ComputeCompatibleFormat(
 
     if (Status != STATUS_MORE_ENTRIES)
     {
-        /* Failed to data ranges */
+        /* Failed to get data ranges */
         return Status;
     }
 
@@ -276,7 +276,7 @@ ComputeCompatibleFormat(
         MixerFormat->WaveFormatEx.wBitsPerSample = 16;
 
 #else
-        MixerFormat->WaveFormatEx.nChannels = min(ClientFormat->WaveFormatEx.nSamplesPerSec, AudioRange->MaximumChannels);
+        MixerFormat->WaveFormatEx.nChannels = min(ClientFormat->WaveFormatEx.nChannels, AudioRange->MaximumChannels);
         MixerFormat->WaveFormatEx.wBitsPerSample = AudioRange->MaximumBitsPerSample;
 #endif
 
diff --git a/reactos/drivers/wdm/audio/sysaudio/pin.c b/reactos/drivers/wdm/audio/sysaudio/pin.c
index 234f43c4a39..edcd3c307b9 100644
--- a/reactos/drivers/wdm/audio/sysaudio/pin.c
+++ b/reactos/drivers/wdm/audio/sysaudio/pin.c
@@ -17,7 +17,7 @@ Pin_fnDeviceIoControl(
     PDISPATCH_CONTEXT Context;
     NTSTATUS Status;
     ULONG BytesReturned;
-    PFILE_OBJECT FileObject;
+    PFILE_OBJECT FileObject = NULL;
     PIO_STACK_LOCATION IoStack;
 
     DPRINT("Pin_fnDeviceIoControl called DeviceObject %p Irp %p\n", DeviceObject, Irp);
@@ -131,7 +131,7 @@ Pin_fnClose(
     PDISPATCH_CONTEXT Context;
     PIO_STACK_LOCATION IoStack;
 
-    DPRINT("Pin_fnClose called DeviceObject %p Irp %p\n", DeviceObject, Irp);
+    //DPRINT("Pin_fnClose called DeviceObject %p Irp %p\n", DeviceObject, Irp);
 
     /* Get current stack location */
     IoStack = IoGetCurrentIrpStackLocation(Irp);
@@ -143,7 +143,11 @@ Pin_fnClose(
     {
         ZwClose(Context->Handle);
     }
-    ZwClose(Context->hMixerPin);
+
+    if (Context->hMixerPin)
+    {
+        ZwClose(Context->hMixerPin);
+    }
 
     ExFreePool(Context);
 
@@ -217,7 +221,7 @@ CreateMixerPinAndSetFormat(
 {
     NTSTATUS Status;
     HANDLE PinHandle;
-    PFILE_OBJECT FileObject;
+    PFILE_OBJECT FileObject = NULL;
 
     Status = KsCreatePin(KMixerHandle, PinConnect, GENERIC_READ | GENERIC_WRITE, &PinHandle);
 
@@ -242,6 +246,7 @@ CreateMixerPinAndSetFormat(
     {
         ObDereferenceObject(FileObject);
         ZwClose(PinHandle);
+        return Status;
     }
 
     ObDereferenceObject(FileObject);
@@ -298,6 +303,13 @@ InstantiatePins(
     /* Let's try to create the audio irp pin */
     Status = KsCreatePin(DeviceEntry->Handle, Connect, GENERIC_READ | GENERIC_WRITE, &RealPinHandle);
 
+    if (!NT_SUCCESS(Status))
+    {
+        /* FIXME disable kmixer
+         */
+        return STATUS_UNSUCCESSFUL;
+    }
+#if 0
     if (!NT_SUCCESS(Status))
     {
         /* the audio irp pin didnt accept the input format
@@ -340,6 +352,7 @@ InstantiatePins(
             return Status;
         }
     }
+#endif
 
     DeviceEntry->Pins[Connect->PinId].References = 0;
 
@@ -349,6 +362,8 @@ InstantiatePins(
     DispatchContext->AudioEntry = DeviceEntry;
 
 
+    DPRINT1("RealPinHandle %p\n", RealPinHandle);
+
     /* Do we need to transform the audio stream */
     if (OutputFormat != NULL)
     {