Field not a BLOB field

This is a bit of a stumper for me...

I have a TDBImage derivative, trying to work with the following queries:

(1)
SELECT
  A.PRIME, A.ALTERED,
  A.ANIMAGE
FROM
  Master A

(2)
SELECT
  A.PRIME, A.ALTERED,
  A.ANIMAGE, A.MASTER_NAME
FROM
  Master A

(3)
SELECT
  A.PRIME, A.ALTERED,
  A.MASTER_NAME, A.ANIMAGE
FROM
  Master A

(PRIME = 32 bit integer, ALTERED = date, MASTER_NAME = string(50),
 ANIMAGE = ftGraphic )

When I try setting the DataField of the TDBImage to 'ANIMAGE', it fails
with a "Field not a BLOB field" in cases 1 and 2, but NOT 3 (it works
just tickety-boo and brings up the picture in 3).  I've tried removing
ALTERED (which is a date field) from the query, but it makes no
difference.

I've tried tracing my code through, and it quite merrily goes through
everything - traces down to the RecordChanged(nil) through to an
Assign to the TGraphicField (which calls the AssignTo, of course,
because TPicture doesn't know about TGraphicField) - seems to get
through almost all that fine, but the Field not a BLOB field comes
from the BDE.

I know there's a possibility I've done something silly and odd, but
if anyone's ever seen this come up under similar circumstances, could
you tell me a little more about it?

Confuzzled :)

  --=- Ritchie Annand