Cannot select pages to display ads

After the most recent update (1.7.57), I am no longer able to select the pages I want the ad to be displayed on. When I do select the pages and save, the selection is not saved. Instead, the radio buttons all come up unselected again. So I am forced to display ad on all pages of the blog, which is not what I want.

http://wordpress.org/extend/plugins/simple-ads-manager/