I've tried that in the meanwhile, but I keep getting the same Exception:
Exception [TOPLINK-3002] (Oracle TopLink Essentials - 2006.8 (Build 060830)): oracle.toplink.essentials.exceptions.ConversionException
Exception Description: The object [oracle.sql.TIMESTAMPLTZ_at_19fae86], of class [class oracle.sql.TIMESTAMPLTZ], from mapping [oracle.toplink.essentials.mappings.DirectToFieldMapping[startdatum-->AUFGABEN.STARTDATUM]] with descriptor [RelationalDescriptor(myapp.Aufgabe --> [DatabaseTable(AUFGABEN)])], could not be converted to [class java.sql.Timestamp].
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