WMEncoder leaves open system handles around after running

[PlayQ]

I am using the WMEncoder (seris 9) object inside a .net(c#) encoding app that encodes a wave file to a wma file. Everytime I create and use the WMEncoder object it leak system handles even after I try to release it via GC. If I let my app running continuously it will eventually crash because it runs out of system resources. My code sample is below. I am following the examples in the SDK.
Please help.

Thanks.
Russell Bonakdar

public void EncodeFile()
{
WMEncoder mEncoder = new WMEncoder();
mEncoder.Synchr onizeOperation = false; // false makes calling Start create a separate thread to cue and set up the device, and returns immediately.
mEncoder.OnStat eChange += new _IWMEncoderEven ts_OnStateChang eEventHandler(O nStateChange);
mEncoder.OnErro r += new _IWMEncoderEven ts_OnErrorEvent Handler(OnError );

// Create and add a source group to the source group collection
IWMEncSourceGro up mSrcGrp = mEncoder.Source GroupCollection .Add("MySourceG roup");
IWMEncAudioSour ce mSrcAud = (IWMEncAudioSou rce)mSrcGrp.Add Source(WMENC_SO URCE_TYPE.WMENC _AUDIO);

mSrcAud.SetInpu t(mFullPath, "", "");

// Set the two-pass encoding flag
mSrcAud.PreProc essPass = (short)(mDualPa ss ? 1 : 0);

// Set current output file name
mEncoder.File.L ocalFileName = String.Format(" {0}\\{1}_{2}.WM A", mOutFolderPath, mMasterID, index);
mCurOutputFile = mEncoder.File.L ocalFileName;

form.AddLogMess age(String.Form at("Encoding WMA: {0} to {1}", mFullPath, mEncoder.File.L ocalFileName));
mSrcGrp.set_Pro file(Pro2);

mEncoder.Prepar eToEncode(true) ;
mEncoder.Start( );

form.AddLogMess age(String.Form at("EncodeFile( {0}) is waiting for the encoder to Stop...", Thread.CurrentT hread.ManagedTh readId));
while (mEncoder.RunSt ate != WMENC_ENCODER_S TATE.WMENC_ENCO DER_STOPPED)
{ // Keep UI messages moving, so the form remains responsive
Application.DoE vents();
}

// try to cleanup after the encoder
mSrcGrp.RemoveS ource(WMENC_SOU RCE_TYPE.WMENC_ AUDIO, 0);
mSrcAud = null;
mEncoder.Source GroupCollection .Remove("MySour ceGroup");
mSrcGrp = null;
mEncoder = null;
Application.DoE vents();
System.GC.Colle ct();
System.Threadin g.Thread.Sleep( 0);
}

[xtomiii]

// after this line
GC.Collect();
// you're missing this line
GC.WaitForPendi ngFinalizers();

// aslo I advide to remove video from source group