The modal popup currently requires that the component output is displayed on the page. Many templates have the option to disable component output on the home page. If that's the case on your site, you'll need to either enable component output or use the standard display mode of the module on the home page.
We should have an update to the module in August that will allow for the modal view to work on pages where the component output has been disabled.
I hope that helps explain, but if you still have issues, just let us know.
Thanks,
Alex