Prefab Sphere Collider reset it's radius

Hi, I found this annoying bug in Unity 5.1.3f1 where I have a object with a sphere collider on it. The object was already prefab so I have a instances of it. When I change the radius of the sphere and clicked on applied, it revert back to it's weird values (e.g. 0.08000183) When I check the prefab source, it shows the changes I've applied. Why does the Sphere Collider radius adjust to a different values I did not set? I am getting irritated that the sphere collider is not keeping it's original values. Please help! Using windows 10 64 bit 8 gb ddr3 ram unity is using 64 bit version.