I'm sorry, I have no idea what the problem is.

However, looking at CPAN, I see that WWW::Mechanize is up to version 0.57.

Maybe the problem you're running into is fixed in that release? In any case, you're more likely to be able to get help from the maintainer if your problem is happening with the latest release.

That latest version was release on July 31 of this year, so it looks like this module is still being actively maintained.
--
Mike