Flickering power led/display

Today my FriendlyARM + 7" lcd arrived.  When powering up I got a blinking
power led/display.  Without the lcd connected, the board started up fine. 
Has anybody else experienced this?  What is the most likely cause: the
power supply or the display itself?  The power supply is a 5V, 1.2 A one
(http://www.watterott.com/en/Power-supply-5V-12A).  Any info appreciated.

cheers!

This was the power supply that was not powerful enough to both power the
display and the board.

I head the same problem. The power cords ware 1m long and very thin, so the
voltage drop at 1A was more than 1V! So even when power supply was giving
5V the voltage at the board was 4V witch is not enough.