Expression blend black line error? border?

Question

Hi

I'm Trying to figure out why I get a black line down the side of my image in Blend 3. I've imported it from an illustrator file and the image is in a mask layer.

    <Grid x:Name="LayoutRoot" Background="White">
  <Canvas x:Name="home_page_1_LAYERS_rgb" HorizontalAlignment="Left" VerticalAlignment="Top" Width="1024" Height="773.999">
   <local:Screen_2 Width="926.035" Canvas.Left="50" Canvas.Top="33.832" d:IsPrototypingComposition="True"/>
   <Canvas x:Name="IMAGE" Width="2500" Height="1600" Canvas.Left="289.396" Canvas.Top="174.823">
    <Image Source="home page 1 LAYERS rgb_Images\Image.png" Stretch="Fill">
     <Image.Clip>
      <PathGeometry Figures="M289.408,679.203 L975.358,679.203 L975.358,236.726 L289.408,236.726 z">
       <PathGeometry.Transform>
        <MatrixTransform Matrix="4.17418020377205,0,0,4.17418019380207,-1207.99103794542,-729.743714955325"/>
       </PathGeometry.Transform>
      </PathGeometry>
     </Image.Clip>
     <Image.RenderTransform>
      <MatrixTransform Matrix="0.239567999267578,0,0,0.239567999839783,0,0"/>
     </Image.RenderTransform>
    </Image>
   </Canvas>

Thanks Judi