DV Info Net - Problem with my new K6

I'm having an interesting problem with my new k6 with a ME66 capsule. I have a slightly older version ME66/K6 set-up that I ran on my xl1s. Not long after I bought my XL2 I went out and bought another ME66/k6 set-up, but during some test shooting there seemed to be a difference in sensitivity. At first, I wasn't sure if it was my settings, the XLR plug, the Capsule or the K6. After a short time of trouble shooting between the old and new I've discovered that the older k6 attached to either ME66 capsule was twice if not three times more sensitive. Does anyone know if this is common on the newer k6, could it be there just not as sensitive or did I get a defected one? I'm still able to get sound but just doesn't seem as clear. Any input will be greatly appreciated. Thank you.