I can confirm that this bug exists in an installed, up-to-date Ubuntu 12.04 LTS and on the Ubuntu 12.10 Live CD. You can clearly see the shadow on a white presentation (screenshot attached).
I can confirm that this bug exists in an installed, up-to-date Ubuntu 12.04 LTS and on the Ubuntu 12.10 Live CD. You can clearly see the shadow on a white presentation (screenshot attached).