Crop sizes different in Photoshop

Please could someone help - I am using C1Pro for converting nef raw images to tiff format. When I crop these images 9x6 12x8 etc. and then batch process them the resulting crop size is often slightly different when they are opened in Photoshop.

I have tried carefully adjusting the crop size before running the batch and sometimes they are correct but unfortunately more often they are not. It has become quite frustrating resizing the images in photoshop and maybe I'm missing something. Any help would be appreciated.