Hello Leon,
Be sure that you first sync annotations (on the old situation) before importing the images into another catalog. When adding keywords in EM these are not automatic 'inserted' into the image. They first only land in the EM database so you have to sync it first (bring the keywords from database into the image).
Also check the settings, when i remember it well there could arise problems with the 'include the GPS field' option. I alway's uncheck this option myself:

Roelof