if you get the message 'invalid field registration' for the Advantage
package at startup it might be a problem with the path to your
Advantage package.
Delphi 2005 (even SP2) seems to have a bug with paths that are too long
or maybe that contains blanks. Installing the ADAC to a path like
"\program files\Borland\Bds\3.0\lib\advantage" solves the issue.

--
Joachim Duerr
EMEA Lead ADS Support, Extended Systems GmbH, Germany
advantage[AT]extendsys.de
Join the European Advantage Conference 2005!
http://www.extendedsystems.com/go/eac2005