Perhaps you need to see if your mat is aligned correctly. It is adhered to the wooden board with double-stick tape. It can just peel right off - that's how you replace your mat if it becomes worn. (I always get my husband to help me with mine. ;-) ). You peel the mat off from one corner & rub the tape off the mat or board. Then, place the mat on the board & shift it around with your cutting guide on your side rail. Once you have it set like you want it. have a helper hold the mat still on opposite corners. Move the cutting guide to the rail at the bottom of the board, making sure that it is straight in that direction, also. If it is, remove the cutting guide, & with your helper still holding the matt in place, gently lift each free corner & put a new piece of tape in each free corner. Then, have helper hold taped sides down while you tape under the other corners. Let me know if that helps. I know how it is to have a piece of equipment that you're having issues with. Good luck! Debbie