Forms Drillthrough Issue for Multiple Reports

Summary:

I've got a form with a single drillthrough report defined. Works fine on the web and Smart View.

If I add a second drillthrough report to that same form, it works fine in Smart View but does not work on the web.

Content (please ensure you mask any confidential information):

When I click on one of these reports, nothing happens. No new tab, no error, nothing.

If I remove one of them, the remaining report works.

Has anyone seen anything like this?