Hm..Anyone ever watch the full Cell Saga on DBZ?

:-/ Well i was into it bout 2 years ago. Anyway, If anyone watched the full Cell Saga, it doesnt make sence. In the begining of the saga, Imperfect cell came from the future using Trunks time machine. Right. Now then at the end, i think the last episode was The Future of Trunks or something like that? Anyway, he kills cell in that episode along with the androids. That doesnt make sence since the cell he killed, was destroied in the past when he took trunks time machine. >.> Idk it just came to thought yesterday. Anyone realize that?