We full-time and keep back of the SD17 set up as a bed always. A few weeks ago, the table cracked. The post holders, I believe, make the center weak, as well as the fact MDF board not that sturdy. It's a problem many experience.
As a quick fix, I added a few PVC pipes as legs under the cracked board.
We have ordered a 1/2 inch finished hardwood sheet of wood to replace the broken one.