Hi,
thanks so much for these hints, Helen.

> Have you set up KeyDescLinks ...

I don't think these apply because it is a direct, simple keylink
relationship similar to Demo 1 in the GSG. There is no subselect or
anything.

The key relationship corresponds to a foreign key in SQL, so it always
matches. Also, the lookup generally works very well - unless the
combobox has the keyboard focus. So I do believe I have set up the
query's links correctly, it's just that it doesn't work when focused.

When it displays nothing, it suffices to press a right arrow key in
order to remove focus from the LookupCombo, and in this instant it will
suddenly display the correct value. Again, the empty combobox occurs
when the master dataset of the keysource dataset moves, so that the
keysource dataset moves also, but the combobox/lookup dataset goes blank
rather than looking up the keysource dataset's key value - if and only
if the combo has the keyboard focus.

If this problem doesn't sound familiar, I guess I'll have to put
together some SQL excerpts ...

Cheers,
Tobias