Does not work with Webforms

I use a form created via the Webforms module and had hoped that this would help prevent double submissions via use of the browser's "Back" button.

Unfortunately, this module does not help in this scenario -- i.e., when form is submitted and Webforms code processes form and creates/directs to another page ... user wants to do another submission and presses the browser's "Back" button and re-uses form ... however, this causes a duplicate posting in the way the form's being used (it gets unique data from a DB table).

It'd be nice if this module would prevent the use of duplicate submissions to the same form when accessed via the browser's "Back" button.