Maybe it is the cutter. I was told that you should buy replacement blades that are the same brand as the cutter. Has something to do with the cutout in the center "hole". I bought a few off brand cutters that were really cheap on clearance. Didn't like the feel of the cutter so took the blades and put them in my olfa. They didn't cut very well(they worked fine in the off brand ones). Have tried the HF ones and they cut like butter (as a few above have said).