When my pool was new, the first time the pump stopped my basket popped up. I called the store and they had me put a rock in there. It doesn't take much room and it weighs the basket down enough to keep it from popping up.

I'm glad to see someone else has this problem.

Just be careful ... I have tried to be lazy and put the basket back without removing the rock and it fell out and lodged itself into the hose connector ... it wasn't a lot of fun trying to pry the rock out.