Exactly there is a lot more confusion among all about the differeniation between the Managed and Unmamanged solution in MS CRM, and most think that the managed solution and unmanaged solution is that managed solution can be removed easily where as the unmamanged can't be but th exact reason among both is that the unmamanged solution has the reference of the component which is in the default solution where as the managed solution contains the whole component and thus when we import and export, we are overlapping the functionality of the component rather than just updating the existing functionality of th component. Apart from the same, an unmanaged or managed component can be traslated visa versa just by updating the bit in the xml, and nothing much.