Projector Toshiba TDP-XP2 with VGA connection to laptop VAIO PCG-5P4L using Vista Service Pack 2 has worked reliably for Powerpoint presentations for 2 years. Occasional blank screen after 20 to 30 minutes idle. Pressing the "Input" button on the projector polls "Computer", "Video", and "S-video" inputs and reestablishes the "Computer" connection via the VGA cable.
Today THIS projector does not recognize the signal from THIS computer at the "Computer" input.
HOWEVER, the VAIO laptop drives two other projectors with no problem using the same cable,
AND the Projector works great with two other (desktop) computers.
What is the likely reason for the incompatibility of these particular pieces of equipment?