Can't Assign Value to Object (Revisited)

[David C. Holley]

When the form on which the object exists is opened directly, the value
is set without any error. However, when the form is opened using the
following statement

DoCmd.OpenForm "frmReservations", acNormal, , , acFormAdd, , Me.Name

Access returns the 'You can't assign a value to this Object' error (#2448).

[Forms]![frmReservations]![txtOutlookEntryId] = newAppt.EntryID

When I try setting other values via the Immediate Window, I get the same
error.

Why would I not be able to set the value? Does it make a difference that
the sub trying to set the value is in a free standing module as oppose
to the form's code module?

David H