After a fresh installation of Lubuntu 13.10 the default background image is distorted (the provided image shows a part of it). All GUI elements are displayed correctly. If I then select a different user in the drop-down list, like the Guest Session, the background is reloaded and displays correctly.
Does anyone know how to fix this problem? I use a MacMini 3,1 with an Nvidia GeForce 9400M graphics card and a 1280x1024 (LCD) monitor.
