Unfortunatelly the error which appeared in MM caused the database to loose the information about title and ablum, so when I replace the file with a converted functional WMA file, this data is also lost, although it still is somewhere in the original file, as the converted version shows it before it is updated from the database ...
So it doesn't seem to make sense to do this before MM can discover this information again in the old WMA files, and update the database.
Any new ideas are always welcome
