intertwingly

David Goodlad: the existing article on the Ubuntu wiki for the T61 says to modify /etc/default/acpi-support, which is only valid for Gutsy. gnome-power-manager in Hardy seems to use the data from the hal-info package instead, now, which is contained in a bunch of xml files in /usr/share/hal/fdi/information/10freedesktop/20-video-quirk-pm*.

This hint lead me to Sleep Quirk Debugger, which enabled me to produce:

<match key="system.hardware.product" string="6457B51">
  <!-- Proprietary nVidia driver quirks -->
  <merge key="power_management.quirk.s3_mode" type="bool">true</merge>
  <merge key="power_management.quirk.s3_bios" type="bool">false</merge>
  <merge key="power_management.quirk.save_pci" type="bool">true</merge>
  <merge key="power_management.quirk.vbemode_restore" type="bool">false</merge>
</match>