I am so glad that the people at Bumbo finally figured this out: the stupid thing needed a seatbelt!
I have the twistiest baby ever, so the seat, even on the floor, was useless. Without any type of restraint, it was an accident waiting to happen. This morning, a voluntary recall was issued. Go here, and you can order a free repair kit.
UPDATE: My repair kit arrived 8/20– less than a week after I ordered it! That was fast. And despite very clear, detailed directions, I installed the belt upside-down. Oops.