I just completed two quilts with solid navy backing and used Hobbs 80/20 batting, and encountered the same problem. When I took the quilt off the LA table I freaked out to see all the pokies! Very disheartening. Those backings were made from 45" wide Kona Fabric. After consulting with other quilters, the general consensus was a thinly woven backing. It was recommended to me to dot each pokies with a navy permanent marker, which I eventually did. Also recommended was to use a smaller needle.
I'm currently working on another customer's quilt, again using Hobbs 80/20 and not having that problem.