How many ounces are you pulling from your lungo pod?
Answer from illy: "The medium roast capsule makes 1 ounce of espresso and lungo makes 2 ounces. Both pods make the required amount of espresso in the same period of time (18-20 seconds). The grinds in the lungo capsules are looser so it allows more water through the capsule."
I measured the coffee in a lungo pod - there was 6.3 grams of coffee in the pod - 0.5g less than in a medium roast pod. So the lungo is roughly an espresso with an extra ounce of water or twice the amount of 46% strength espresso.