Hi, I've a lot of problems with my application because some detail
queries don't work anymore after upgrading IBO from 4.3.Aa to 4.5B.
I noticed this problem but I thought that was a more "permissive"
behaviour of the old IBO with queries with grouping or union, but
today I've faced the same problem with two "simple" queries, so I
think that is a real bug instead.
Here what I had and the different behaviour regarding to Masterlink
and KeyLink setting:

Master query:
SELECT BANCA_ID
, DESCRIZIONEDISP
, SPORTELLO
FROM BANCHE

KeyLink
BANCHE.BANCA_ID

Detail query:
SELECT CONTO_CORRENTE_ID
, BANCA_ID
, NUMERO
, DESCRIZIONEDISP
FROM CONTI_CORRENTE

KeyLink
(auto)

MasterLink:
a) CONTI_CORRENTE.BANCA_ID=BANCHE.BANCA_ID
this worked fine in 4.3.Aa, but in 4.5B does not anymore (the relation
is not build, so detail set stays empty)

b) BANCA_ID=BANCHE.BANCA_ID
c) CONTI_CORRENTE.BANCA_ID=BANCA_ID
d) BANCA_ID=BANCA_ID

b,c,d work fine

Removing KeyLink
BANCHE.BANCA_ID
or setting it as simply
BANCA_ID
in the master query has made a) work as before

Any clue?
regards
Marco Menardi