X problems on Dell Latitude w/i915 graphics (and Fn-key questions)

[Toralf Lund]

We're having problems with the X server when running Fedora or Red Hat 
Linux (i.e. we've tried both FC3 & older stuff) on a Dell Latitude 610 
notebook with an Intel 915 graphics chip. Firstly, no driver but "vesa" 
appears to work at all, but we don't mind that too much. However, we 
can't get a correct display with that either. Symptoms:

    * A black screen is displayed by default.
    * When using an external monitor instead of the built-in LCD screen,
      everything works fine.
    * If starting up with external display, then switching to the
      build-in one via and Fn-key combination (Fn+F8 in this case), the
      built-in one also works.
    * The same is true after starting with the internal one (and getting
      a black screen), then switching to external and back to internal.
    * In the above two cases, display is once again lost if we switch to
      a different VT via Ctrl+Alt+F-keys, then back to the X server.

Any ideas how to get around this? I mean, how to get the internal 
display to work directly?

Related question: What exactly happens when the Fn-combination is 
pressed? I mean, I've sort of seen this operation as akin to pulling out 
the cable to the monitor, then inserting another one, but to get the 
behaviour described above, there must also be some kind of software 
signalling involved, mustn't there?

- Toralf