Why do hard coded filter criteria succeed and variable ones fail on zc-component?

Why do hard coded filter criteria succeed and variable ones fail on zc-component?

Hi I'm very confused.  Why does #1 below work but #2 does not?

  1. <div elName='zc-component' viewLinkName='Properties_Report' params='zc_Header=true&amp;ID=2811360000000011231'>Loading View...</div>

  2. <% Property_ID = 2811360000000011231; %>
    <%= Property_ID %>
    <div elName='zc-component' viewLinkName='Properties_Report' params='zc_Header=true&amp;ID=<%= Property_ID %>'>Loading View...</div>
On the surface, it seems to be a simple case of variable substitution. 
On the other hand, I have been fighting this for days now.
For #1, the Properties Report correctly shows only a single entry.
For #2, the Properties Report incorrectly shows ALL entries, regardless of whether they match the filter criteria.