Fatal error: Cannot use string offset as an array in Admin Coupon Area

I’ve installed Marketplace and I’m getting this error when I click on the “Coupon” tab in the admin area and this is the error I get…

Fatal error: Cannot use string offset as an array in /home/user/mysite.com/wp-content/plugins/marketpress/marketpress.php on line 5607

I’ve uninstalled, reinstalled, plugins on, plugins off…no dice.

Any words of wisdom would be greatly appreciated.