I have a Gaiam flower power, green ball and the replacement valve doesn't stay in? There is nothing for it to snap into on the ball. The ball just has a hole for the pump to go into and nothing else....is it missing another part? I'm not familiar with this product and when I purchased this it was missing the valve, so I purchased replacement valves thinking that would solve the problem, but it's still not working. The valve is just blown out by the air pressure. Please help!