The problem was indeed caused by the gnome-settings-daemon package. I have attached the debdiff with a workaround which simply suppresses this misleading "Printer XXX may not be connected", triggered whenever CUPS reports "connecting-to-device" which it does on every job. This is a workaround as we are after string/UI freeze. The fix is to improve the text, for example to replace it by "Connecting to printer XXXX ...". The same text improvement should also be done in system-config-printer.
The problem was indeed caused by the gnome-settings- daemon package. I have attached the debdiff with a workaround which simply suppresses this misleading "Printer XXX may not be connected", triggered whenever CUPS reports "connecting- to-device" which it does on every job. This is a workaround as we are after string/UI freeze. The fix is to improve the text, for example to replace it by "Connecting to printer XXXX ...". The same text improvement should also be done in system- config- printer.