line21 decoder usage causing a memory leak

Question

I am building a simple render application which reads the data from an 
asf file and render it with VMR-9. 

It is being observed that the usage of Line21 decoder causes memory 
leak of around 6MB. 

The line 21 decoder is just connected but it is not fed any cc data 
since my source has no cc samples. 

After the graph build and cleanup I observe the process private bytes 
gradually increase on each itteration. 

If I dont add the Line21 decoder I dont see the memory leak.Also have 
checked the code with bounds checker tool which does not show any 
leak. 

here is the line21 connection to the vmr.

  8. [Line-21 Decoder 2]/(XForm Out) -> [Video Renderer 9]/(VMR 
Input1) 
      Major:   MEDIATYPE_Video 
      Subtype: MEDIASUBTYPE_ARGB32_D3D_DX9_RT 
          bFixedSizeSamples:    TRUE 
          bTemporalCompression: FALSE 
          lSampleSize:          1382400 
          cbFormat:             1128 
      Format:  FORMAT_VideoInfo 
      VIDEOINFOHEADER: 
          rcSource:             (0,0,720,480) 
          rcTarget:             (0,0,720,480) 
          dwBitRate:            331444224 
          dwBitErrorRate:       0 
          AvgTimePerFrame:      333667 
      BITMAPINFOHEADER: 
          biSize:               40 
          biWidth:              720 
          biHeight:             -480 
          biPlanes:             1 
          biBitCount:           32 
          biCompression:        0x00000003 
          biSizeImage:          1382400 
          biXPelsPerMeter:      0 
          biYPelsPerMeter:      0 
          biClrUsed:            0 
          biClrImportant:       0 

Any idea  what could be going wrong.