Hi, you don't need modes in xorg.conf specified.In VirtualBox menu you have option Auto-Resize Guest Display (Host + G).Then when you will maximize window with Guest or switch it to full screen your resolution in guest will change automatically so you will have 1643x1423 and so on (depend on your monitor size and other things).
And maybe try delete Section Device with nvidia driver.I don't have separate section for Intel,but maybe it's only case of Intel.You must try it. -- This message posted from opensolaris.org
