flickering laptop screen

my laptop seems to start flickering after it has been on for 15 minutes or so. it does seem to get a little hot. when i hook it up to a desktop monitor it goes from widescreen to regular (external monitor is not widescreen) stops flickering but when i unplug the other monitor it starts again when it switches back to widescreen. if it was a connection or overheating wouldn't the laptop monitor flicker even when the other external monitor is hooked up?

 

Welcome to WindowsBBS.
Sounds a little like Graphics problem. Have you tried for update Drivers for your Graphics card? If it's built in to m/b you may need to update the BIOS. Neil.