Does anyone else have trouble with blades not cutting when clipping heads? If I use my big clipmasters, they work great unless the blades are getting dull. But if I use a smaller clipper like Andis 2 speed, with a coarse or medium blade, it seems to clog on the hair (esp. when clipping head the first time and the hair is long) and then the blades won't cut at all. And this after I just sharpened the blades. Any ideas?