Ok, did some research on this problem. Over at ****** forums some folks have an older thread concerning this problem and have had limited success at getting the problem solved.
Seems that the bios senses the the power cord is not present from the acpi and changes the selected settings in the bios which pclos looks for when booting. Naturally if one boots into pclos with the power cord disconnected pclos tries in vain to use the original settings to boot and fails.
Apparently there is no bios downgrade to just use the gt260 cards and I can't see any way to remove or disconnect the nvidia 9400 graphics card?
Would it be possible to write a script for xorg that would select the proper card on boot regardless of which one is needed according to the bios change? Is anyone here savy enough to help with that? I know I'm not