Follow-up: /usr/share/themes/Ambiance/gtk-2.0/gtkrc contains the following lines:
#include "apps/gedit.rc"
include "apps/gnome-panel.rc"
include "apps/ubuntuone.rc"
…and in fact these three files are the only ones containing configuration like: engine "pixmap" { …
Commenting out the lines for gnome-panel.rc and ubuntuone.rc causes the error messages to disappear. The appearance of the Ubuntu One control panel changes, but otherwise it continues to work properly under both the "Ubuntu" and "Ubuntu 2D" sessions.
I also note that I do not have gnome-panel installed on any system I've upgraded to 11.10 from 11.04.
Follow-up: /usr/share/ themes/ Ambiance/ gtk-2.0/ gtkrc contains the following lines:
#include "apps/gedit.rc" panel.rc"
include "apps/gnome-
include "apps/ubuntuone.rc"
…and in fact these three files are the only ones containing configuration like: engine "pixmap" { …
Commenting out the lines for gnome-panel.rc and ubuntuone.rc causes the error messages to disappear. The appearance of the Ubuntu One control panel changes, but otherwise it continues to work properly under both the "Ubuntu" and "Ubuntu 2D" sessions.
I also note that I do not have gnome-panel installed on any system I've upgraded to 11.10 from 11.04.