Dear Treasurit,
I was a rep for a few years, and some people complained of that. We're so used to being afraid of it slipping when we're doing it alone, that we start getting "cutting -shy".
If your mat is lined up, all you have to do is squre the top of your fabric, and use the speed guageto mark your cuts. Since the QC-2 is built like a drafting board, the accuracy is in the mechanics of the head & rail system.
So, insert your fabric under the clamp bar, close the clamps after lining up the edge of your fabric with a vertical line on the mat.The when you insert your cutting guide into the side railing, it will be square to the fabric. When I was teaching my daughter, she said"Yeah, but I can wiggle the far end!" Just a little exasperated, I said "Yeah, & I can put a pot holder in the freezer door & it won't freeze. Just don't doit!" Well, we made peace, and I hope you will,too, with your unit. Debbie