i810, starting X without a connected Monitor on DVI

[Felix]

Hello List,

A JVC LCD with 1360x768 works fine at this resolution with a new Intel
Q965 DVI output. (after the ususal tricks. Modelines, 915resolution,...).

But now I have to start the Intel Q965 without a connected DFP on DVI.
More exact: Without ANY connected display on DVI or VGA.

If I later on connect the DFP, I don't get any signal. I assume the
active head is VGA, not DVI.

With a few tricks (  Option "DevicePresence" "true" ) I am at least able
to get a signal, after I restart X. But only in 640x480 and not the
native 1360x768.

I didn't find a possibility to simply say: "Use DVI at 1360x768 without
looking for any DFP" and I tried a lot Options.
For example
  Option "DDC" false"
  Option "NoDDC"
  Option "DisplayInfo" "false"

Any ideas?

Greetings, Felix