Land Rover Repair: fault code 0300, 0301, 0303, 0305, simultaniously, firing on all cylinders

Question
I get 4 fault codes (0300, 0301, 0303, 0305) with my scanner. Before this occurred, I installed 6 new NGK Iridiums. I find it hard to believe three separate coil packs and spark plug wires could fail simultaniously.  

What do you think is wrong? The car did run rough once like it wasn't firing on all cylinders.

Answer
If the truck were here ar Robison Service the first thing we'd do would be to change to the correct Land Rover plug, because we have found these motors to be sensitive to that.  Also, you do often get simultaneous failures of old plug wires as they fail when you pull them apart to change the plugs.  So bad wires would not be a surprise.