Mega 2560 -- Digital output Ports K & L -- Does Not Work as digital outs?

Hi,

I am attempting to use analog in ports K and L as digital outs on a 2560. All the references I've seen say it should work and no extra code to set the port as such......

Code snippet using direct port manipulation

// First set the data direction registers
DDRF = B11111111; // GREEN LEDS - "ARMED"
DDRK = B11111111; // YELLOW LEDS - DISARMED OFF HOOK"
DDRL = B11111111; // RED - "ON HOOK"

// then manipulate the port
PORTF = B01010101; //Light every other LED on each port as a test
PORTK = B01010101; //
PORTL = B01010101; //

Thanks in advance for any thoughts on this

Paul