Can you please provide an nvidia-bug-report? See: http://www.nvnews.net/vbulletin/showthread.php?t=46678
There are some displays on newer laptops that require support for ACPI methods which are not yet implemented in the NVIDIA driver in order to be correctly detected. I suspect that you may have one of these laptops, and information from the nvidia-bug-report would be able to confirm this.
We are working to provide support for these ACPI methods, and therefore the built-in displays on laptops that require them, in future versions of the NVIDIA X Display Driver. Until such support is in place, the vesa driver should be able to provide basic display functionality on your system.