I finally found it to be related to #280718 (gnome-cups-manager: floods central cups printer server with requests).
You should then probably reassign this bug to gnome-cups-manager, and probably merge it with #280718. I have ~30 Sarge workstations running GNOME and so polling constantly the CUPS server for new printing notifications (as CUPS is not yet DBUS-enabled, at least in Sarge). I fixed it by removing gnome-cups-icon from the user sessions. One may want to patch and rebuild libgnomecups1.0-1 instead with a larger UPDATE_TIMEOUT in gnome-cups-printer.c. Still, cupsd is spending most of its time in the "time" syscall. Thanks anyway. -- Jérôme Warnier FLOSS Consultant http://beeznest.net