Current code looks like this in GradingService, fibmatch, line 1926(trunk as of today)
p = Pattern.compile(regex_quote,Pattern.CASE_INSENSITIVE );
Should look like this:
p = Pattern.compile(regex_quote,Pattern.CASE_INSENSITIVE|Pattern.UNICODE_CASE);
Whitout the later line, using fill in blank with swedish character(and other than US-ASCII) with case sensitive unchecked will result in incorrect scoring.