Troubles with umlauts in full-text search (JCR-SQL2)

Hello modeshape team,

we're having troubles with full-text search in combination with umlauts.

Generally full-text search is case insensitive, but it looks like it's case sensitive for umlauts contained in the search text.

Let's assume we have a content having a property called title with the value 'Änderung'.

Here is our example query:
select * from [content] where CONTAINS(title, $searchText)

If searchText is replaced with 'änderung' then the query doesn't return any results.
If we change the searchText to uppercase ('ÄNDERUNG') or remove the umlaut ('nderung', 'NDERUNG') the query returns the expected results.