When I worked in Germany, my secretary was German born and married to an Austrian national. On marrying him, she had automatically gotten Austrian nationality and had to give up her German nationality.

A few years later, they moved back to Germany because her husband had been offered a job in our plant. The Germans would not give her a work permit, despite her having been born in Frankfurt. Our plant manager pulled some strings and arranged to get her work permission by offering her a job in the same plant with her husband. It does seem really silly that they wouldn't allow her to work otherwise - but government regulations generally have nothing to do with common sense.
Cheers,
Bev