problem with subform linking

[Mary]

I have a main form with one subform that is used to record test
scores. The main form has the following fields:

WratStudentID ( a combo box with 2 fields - student id and student
name - . Stores the id)

WratGradeLevel
WratDateAdmin (mm/dd/yyyy)
WratForm

The subform has the following fields:

WratScoresID ( the student id)
DateAdmin
SubtestID
RawScore
StandardScore
Percentile
GradeEquivalent

There are 4 subtests that are entered via the subform.

I am linking them as follows:

Link child fields: WratScoresID; DateAdmin
Link master fields: WratStudentID; WratDateAdmin

Everything works fine when entering a student for the first time. The
date administered and student id are properly written to the subform's
underlying table. However, if I go to enter another main record for
that student, as soon as I enter the student id, it pulls up all the
subform records that are out there for that student, even though the
date administered has not been entered. It appears as though it is
ignoring the Date Admin linking criteria.

Any Ideas?

TIA