When trying to sell an offline energy module I get the message: "Cannot Sell Module. Max energy would drop too low. Uninstall some relays first."

I've had this problem several times before and to be able to sell the module I have to install it first and then sell it. This usually means that I have to uninstall something else which lowers that modules condition by 10%.
It should be possible to sell any uninstalled module. Is there some error in the energy level checking routine?
Have anyone else noticed this?