Question : Problem: External monitor Flicker

Ive a toshiba satelite pro laptop and whenever we hook it up to an external monitor the external monitor has horizontal lines flickering down the screen.  Ive tried 2 different monitors and 2 VGA cables.
The laptop screen is fine.
Im guessing it could be some form of interference, but ive tried moving everything a reasonable distance from each other.

any suggestions?

Answer : Problem: External monitor Flicker

Could it be the laptop?

If you're running off power try switching it to battery and vice versa.   Also if on power put the laptop on a different wall socket to that of the monitor.