Problem with Checkboxes in Results Table

I've tried using the code examples that are posted here to prepend checkboxes in a table. It works fine for a regular stand-alone table but when I use it the table displayed as my search results it does not work. 

I am using the correct view-key which I've checked and rechecked. I have verified that the code is running by creating console output but the checkboxes do not appear. 

Is there a reason why this functionality would not work in a results table?  Is there something else I need to do to adapt this to search results? 

Thank for any suggestions! 

Any ideas folks? It works just fine in a regular table but fails to add the checkboxes to a search results table. Does something need to be implemented differently to get this to work with search results?