I have an RCA gizmo which copies CD's. Before a new copy can be played in another player, it must be finalized. If it's not finalized, it will play in the RCA and seem perfectly all right.

Sometimes a CD won't play because it's not seated firmly in the player. If it's at all whopper-jawed (note correct use of hyphen AND apostrophe), the equipment may say it's not there or that the D drive is not there, or some such baloney.