Try looking at the TruCut rulers and rotary cutters at
http://www.graceframe.com. The rotary cutter rides on a ridge on the ruler. It has improved our cutting accuracy 100%. No wobbling of the rotary cutter makes a difference. I also put their brand of stickers on the bottom of my rulers. They really help hold them in place. I have just had to learn to pick up the ruler and place it, instead of sliding it like I did before