When converting a PDF, please convert boxes to tables (with one cell), not to pictures of a box. Boxes are usually in forms for people to write in. You can't write in a picture of a box in a Word document! If the box was just supposed to be a picture of a box, it will still be a picture of a box if it is formatted as a table. Please default things to making documents have editable content. And keep doing better than Word converting PDF's!