Comment 9 for bug 869293

This is in now way a scientific statement but i noticed when there is a conflict between the wallpaper plugin and the system settings with regard to the wallpaper being used, the errors:

(compiz:7240): GdkPixbuf-CRITICAL **: gdk_pixbuf_fill: assertion `GDK_IS_PIXBUF (pixbuf)' failed
WARN 2011-10-24 21:52:05 unity.bghash BGHash.cpp:390 Passed in a bad pixbuf, defaulting colour

show up in .xsession-errors

If the same wallpaper is nominated in system settings and in the compiz wallpaper plugin, then those errors dissappear. At least that is the case for me using ATI graphics and fglrx