By attempting to contact the author you have already extended the courtesy that you are supposed to extend. Do you think that Mandrake asks for Red Hat's permission before extending the Red Hat Linux distribution's source code?

Indeed, people are always coming out with unusual Linuxes for PDAs, computers without hard disks, etc. The developers don't ask for Linus's permission, nor should they. That's why it is called open source. Open means anyone can use it. Use includes distribution. You especially don't need permission if permission is not available.

I would upload the new module to CPAN and stop looking for the original author. However, I would make certain that my new module profusely credited the original author.

Even if you post an updated module and then don't maintain it, users are no worse off than they are with the current module, which is also not maintained.