Thx for the replies. It's definitely the lower panels. Of the 12 total lower magnets, 3 or 4 of them aren't even grabbing. Tried switching w/ to magnets that seemed to still have some strength, but still get same issue. As for the frame...still very rigid, no sag. I just recently put it back together after it had been sitting in a box for years after my late dog somehow knocked it off the table I had it displayed on. So, it hasn't been together for the full 15 years I've owned it. I'm sure if it had, I would have issues w/ the frame work sagging under all that weight