Zimbra query with "text-match" an collation

[cte]

Hi guys,

I have made caldav queries on a zimbra 5.0.14 to retrieve calendars with given Properties matching a given pattern.
i.e: All calendars with a SUMMARY = "blablabla".
According to the RFC 4791 Section 9.7.5. "CALDAV:text-match XML Element", the text that is in the query must be a SUBSTRING of the text I look for.
Zimbra 5.0.14 seems only to want a perfect matching text. I can't make a query with only "blabla".
Is it a bug that is fixed in newer versions ?