I know there's probably another spot to post this but since I've seen many people complaining about it I thought I would start a new topic.
If you have the factory ladder for the Happyjack bed system see the picture below for a cheap solution. I have about $12 invested and about three hours total of my time.
I used 1x4 and cut them to 10 1/2 inches long. Then angled the corners and sanded to prevent sharp edges. Picked up a small can of stain and flat head sheet screws from Lowe's. I then drilled 4 pilot holes into each step (wood and ladder). After screwing the ladder down I placed the grip tape I peeled up prior to putting the wood on. I was going to buy more but was surprised it was still very tacky once I pulled it off.
Viola, no more sore feet!