howto enable gpu support without a monitor connected

I want to enable gpu support on a linux lxde rendernode which has no monitor.
I can only choose CPU. Why can blender 2.71 not find the gpu when there is no monitor connected.

I realise now that I was starting blender with the vncviewer.
Starting blender with ssh is giving me Unable to open a display.
That sound logical but howto solve and get gpu support.

Hi, only guessing but without display the driver modul is not loaded?
You can make or buy a display dummy.

Cheers, mib

O sorry for not posting I already did as you can see.