To verify the calibration for both images, you can open each image independently in a raster project and confirm that the calibration settings are exactly same for both images. If they are, note the coordinates of a common point on both bitmaps. If the coordinates are not the same, then the images aren't going to line up when you import them both into a vector project. You might need to re-calibrate one to match the other.
Updated August 2, 2018