Hello,

I have found the solution, but I do believe that this needs amending.
It's a totally unecessary pitfall. It has nothing to do with SQL, just
with the current rows of queries. It happens only when the grid's query
is a slave itself ...

When the top master moves, the grid shows totally different rows. Now,
the row with the active combobox is not the active row of the query!
Solution: turn on AutoFetchFirst in the grid's query.

Here's the hierarchy of my three Queries:

MASTER dataset
-------------------------
ID Integer (primary key)
Name char(30)
etc.
(describes a person)

MAIN dataset for the grid
-------------------------
ID Integer
TYPE char(3)
AMOUNT double precision
(describes amounts such as
rent, etc.)
primary key is (ID,TYPE)

TYPE is a foreign key ...

LOOKUP dataset
-------------------------
TYPE char(3)
Description char(30)


Cheers,
Tobias