we had the same problem
soution: Whise installer
we bought a competetive update to instal shield
it works nicely
eveything gets installed

you can download a 30 day trial version to test it for you.
in the installation it only says "not for redistribution".
this will be gone if you put in your licence Key

cost app 250$

Instalschield 12 express did not install all DBI components under Vista Business. thats why we changed.
Dirk