NDBM doesn't seem to be available on linux
That's strange - I have it on my Debian sarge system, and I don't remember it's ever not being there. Have you tried

use NDBM_File;
[download]

It works for me, and if it works for you, your problem is solved. If that fails, and you don't have too many files (and they don't contain too sensitive data), I can transfer them for you for free. (I have access to both Linux and Solaris machines). MSG me and we can arrange details.

If you do have too many files, I'll be quite happy to charge you a fair price ;-)