Hibernate on docking station, then waking up without docking station

(Dell Latitude D600, running SuSE 9.2) When hibernating while docked, then waking up un-docked: the graphics screen is blank. ctrl-alt-f1 successfully goes to the text screen, but the graphics screen is blank. Killing/restarting X brings the graphics screen back (but ctrl-alt-f7 does not). On previous (Toshiba) laptops, there's a function key for switching from external to internal display. The Dell seems to have the same function key, but it doesn't do anything. Any ideas? Thanks, Chris