This has been discussed many times, and I really did not expect to see that bug anymore, but...

If you enter text with umlaut characters, FCKEditor will automatically escape these. Now when you try to search for a word with an umlaut you're out of luck.

Possible work-arounds:

1. Turn of escaping of latin special characters in FCKEditor (FCKConfig.IncludeLatinEntities = false
2. encode your query term
3. or, as Boris once proposed: save the content once in the escaped version and once without escaping