TimeStamp instead of Date Object behind @Temporal(TemporalType.TIMESTAMP)

As stated in the java api (http://java.sun.com/javase/6/docs/api/java/sql/Timestamp.html)
"Due to the differences between the Timestamp class and the java.util.Date class mentioned above, it is recommended that code not view Timestamp values generically as an instance of java.util.Date. The inheritance relationship between Timestamp and java.util.Date really denotes implementation inheritance, and not type inheritance. "

A Timestamp object should not be hided by a Date object. Therefore hibernate should no place a Timestamp object behind that.

@NotNull
@Temporal(TemporalType.TIMESTAMP)
private Timestamp createDate;

Instead hibernate has to do something like this behind the scences:
createDate = new Date(createDateTimestamp.getTime())