Pretty much same problem OP was having here: http://www.gamefaqs.com/boards/979998-kane-and-lynch-2-dog-days/56028789 except mostly from behind cover. Either the cover itself or Lynch will be blocking the crosshairs. I can hold down the aim button and the camera very VERY slowly moves to where it should be but that can take 10-15 seconds, so not exactly practical in a shoot out. It only started happening in the level "Resurrection". Running Steam ver, anyone else have this problem?
I played through the entire campaign and didn't experience this problem. On my second play through in co-op I experienced it once during "The Deal" mission. It's a bug unfortunately, not a very common one though based on my experience.