title: WndProc message = 49619 -what is it?
body: <p>I'm debugging a dragging bug in wpf and have subscribed to wndproc.  I'm getting a message ID of 49619 with wparam=0 and lparam=0.  I've exhausted my google efforts and have been unable to uncover what the name of this window message is.  </p>
  
  <p>If you know, great. If you can provide a website that includes it in its listing of window messages, that's even better.</p>
  
  <p>hex value = 0xC1D3</p>