Hey! So I've tried a few things now, and I'm stumped. I initially thought something was wrong with my lens, because it always seemed to not be able to focus, but now I think it's my body. I took a different lens from my friends camera and we swapped (he has an original rebel). my lens worked great on his camera and his lens didn't work on mine. Everything else on my camera works great, but for some reason it seems to have an issue with auto focusing. What does this mean?