Ubiquity Gtk frontend looks & works correctly in many themes as seen in: Ubuntu, Xubuntu, Lubuntu & Ubuntu Studio. Therefore I do not believe this is a bug with ubiquity, but rather a bug in the theme engine.
The background shadow around the tickboxes on the prepare page is custom theming which is/can be wrong and that part is a known bug pointed out earlier.
Ubiquity Gtk frontend looks & works correctly in many themes as seen in: Ubuntu, Xubuntu, Lubuntu & Ubuntu Studio. Therefore I do not believe this is a bug with ubiquity, but rather a bug in the theme engine.
The background shadow around the tickboxes on the prepare page is custom theming which is/can be wrong and that part is a known bug pointed out earlier.