Michael,
It's hard to say what the issue is without having an actual file to examine, but it may be that you mounted a lens that the camera doesn't "understand" fully, like whether the lens was made for APS-C or not. If the lens is designed for full-frame (looks like a zoom with 23mm in the range), then the camera may just call it as the 35mm equivalent being the same as what the camera reports. Normally a camera will write two Exif tags, one with focal length and another with the 35mm equivalent (which might be different or not). But the camera could only write one tag. I would need a sample file along with a description of the lens that was mounted (make and model).
HTH...
--dennis