OnUpdateRecord-Event gets not called - WHY??

Hi all!
When I try to catch a OnUpdateRecord-Event of an DataSoucre (Table or
Query) to call a UpdateSQL-object, the event seems not to happen, but
the update takes place!!! (it is a query on 2 tables, so it is
requestlive, the updateobject is NOT set, and still this happens). Any
suggestions or other ways to realize a updateable query on 2 or more
tables? Thanks in advance,