Having issues with IIS7 URL rewrite

Question

I'm trying to rewrite the following URL, but I always get a 404 error. I know that the Url Rewrite is working because I have other rewrites working. Any idea what I am doing wrong?

    <rule name="PixelTracking">
      <match url="^pixel([0-9]*).png?OrderTotal=([0-9]*)&amp;OrderID=([0-9]*)" />
      <action type="Rewrite" url="^Confirm.aspx?StoreID={R:1}&amp;OrderTotal={R:2}&amp;OrderID={R:3}" />
    </rule>