One question perhaps you can answer. Do the other distributions of Perl and this DB_File module come with that module linked to a particular version of the Berkeley DB engine, or is it left to the server administrator to decide which version of the DB engine he/she is going to use?
Yes, it is left to the server administrator, as it depends entirely on what version of libdb is installed
If the system on which it is being installed, doesn't have libdb, then DB_File won't be installed
If you view http://ppm4.activestate.com/author/PMQS.html you can see, that on some platforms DB_File is available, while it isn't on other platforms