BE 2012 HTML reports using wrong browser

I'm using Backup Exec 2012 SP3 on Windows Server 2008 R2 with Mozilla Firefox set as the default browser. But if I create a report in BackupExec in HTML format it is invariably opened in Internet Explorer instead. What's more, closing it triggers a security warning about content from "about:internet" being blocked by ESC.

How can I get Backup Exec to honor my default browser setting?

Thanks,
Tilman