It is frustrating to get the angles to line up, that is for sure. Try the glue basting, if that does not work, this might, it is time consuming and I learned this from a pro that enters quilt shows to win. Let me know if it works for you. Hand baste, eww, I know, right? Just one or 2 stitches at each intersection, leave the thread hanging and just go down the block. It takes a little longer than pinning but before you sew you KNOW it is lined up, and the stitches are easy to take out. I have not done this yet.