My problem is not slippage, at least not so much. My problem is getting the fabric actually cut. Even with a brand new blade, even cutting single layers, I get a lot of skips, where the fabric just isn't cut. If I go back, then the 2nd cut doesn't quite line up. I have an olfa 45 ml that I use mostly. I work on either my dinner table or the kitchen counter, the height doesn't seem to make a diference. I end up either using scissors or for strips, tearing. Any advice here?