Nikon 18 to 70 AFS-DX lens focus erroers

Question

Hi, I use this lens on a Fuji S3 and D300 Nikon. I have had it a year or so and it`s been fine. However with shots taken at my last wedding some of the images were out of focus, the focus was more on the background. The focus point was on the subject as I checked this in Nikon Capture (Raw Files).The problem is on both cameras which points to a lens problem. Are there any known "backfocus error" issues with this lens?
Thank You