NSFetchedResultsController, CoreData, SectionIndex and special chars (Umlaute..)

I am having problems with NSFechtedResultsController and using the created sectionIndex(data is coming from a CoreData storage). It seems to mix up the indexTitle ver开发者_如何学运维sus the sectionName e.g. sectionName is "Ä" and sectionIndex is "Ƒ" (0x0191) regarding the unicode char. This seems to be the case with all special chars. this can lead to crashes in case the user is able to use the special chars.

Is this is a known problem or does anyone know a workaround? Apple Addressbook app seems to collect all special cases under sectionIndex "#". Wondering if I should write a ton of code to workaround or if someone already did it? or just get rid of the section index.

thanks a lot. Jens

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Answering my own question: using UILocalizedIndexedCollation seems to be a possible solution. Trying to get it playing nice with core data and NSFetchedResultsController now.

--Jens