My experience with deploying windows clients against fb 2.1 server is
that fbclient.dll looks for firebird.msg in its parent dir (dunno
why). Never tried setting FIREBID env. var, or the registry.

I currently can't find an updated (i.e. for fb 2.1) client deployment
procedure anywhere on the net (if you know of any, please drop a
link).

Ideally, that procedure would just say "copy matching fbclient.dll and
firebird.msg near your executable". I don't know why it has to be more
complicated than this.