Civic EG

I'm running the skunk 2 pro s full coilover and I have noticed something very odd. When I have a full tank of gas my car rides pretty good. When I get down to an empty tank it wants to bounce a little. I wondering if I need a different spring rate in the back? these thing have less than 10,000miles so I dont think they are blown. what do you guys think?

less weight in the rear with an empty tank will "bounce" more. The way things work.

yeah what I was lookin for is a different spring rate that might help with this problem.