David,

>One query: Why do I have to set the connection for both the transaction
>and the query?

aren't you forgetting that a TIB_Transaction may have several
TIB_Connections, whereas a query can only operate on one connection? I
don't know whether it would be feasible to make IBO understand that it if a
TIB_Transaction only has one TIB_Connection associated with itself, then
any queries associated with the TIB_Transaction should use that
TIB_Connection, but we definitely need to be able to specify a
TIB_Connection on the TIB_Query when several TIB_Connections are associated
with the TIB_Transaction.

>If a query's IB_Connection property is set to <default> does this use the
>transaction's connection?

I don't know, but I would expect an error to occur at runtime if it didn't
(well, provided you've changed your SYSDBA password from masterkey).

Set