why are you cutting on the floor? I've been quilting almost forever & I've tried all the cheap shortcuts but I find that Olfa blades & the "old style" Olfa cutter give the best results. If you're cutting in the same spot all the time, the mat will wear out & then the cutter skips. I have also been quilting so long I've actually worn out a cutter (or two). the edges of the plastic behind the blade get worn. Another thing that is possible is that you have 2 blades in the cutter. Don't laugh you would not be the first person to do this. they're very thin & CAN stick together. good luck