(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.