Anyone else having issues with Polar Pro filters not easily threading on? I bought a 6 pack, and a 3 pack of gradients. They dont seem to be the same thread size or count. Ive been sent replacements by Polar Pro (without hesitation) and while they fit better, they still dont seem right compared to the stock lens cover. Now, I am wondering if the threads on the P4 are slightly different than the P3?