> Since we are absolutely shure, that values for primary keys only come
> from reading the generator, this is a case, that should never happen.

If the Primary key definition is part of the table definition this
should never happen, the engine should reject any attemts to insert
duplicate keys.

> So my question is, under which circumstance is it possible, that the
> latest value of the generator is not written properly to the database
> file. I checked and "Forced write" is on for the database file.

Forced write is important - especially if the DB-engine can be killed
by the application.

The problem "something i'nt written to disk" can also be caused outide
your application (e.g. power fail or HDD-error).

Elmar