HST and new backend

Hi, We have developed a HST Application and used it since ca. 8 Month. Some days ago we became a new backend (from SE 4.11 to SE 5.01 UD2) and since then we are unable to store Records containing date types. The Envoironment on the Servermachine is absolutly unchanged ! I think that the way SE handles Environmentvariables has changed. Is this true ??? From the backend we get dd.mm.yyyy but when we try to put this back the engine wants mm/dd/yyyyy (converting serials to mm/dd/yyyy wins). I looked into manuals, relasenotes etc. but found nothing indicating such a change !!! We use an DEC AXP 3000/600s with OSF1 2.0 and DOS/WIN Clients. DBDATE is set to DMY4. Any help on this available ??? hb (System Adm.)