in reply to WWW::Curl code works on one server not another.

Your problem is most likely in the libcurl binaries being different on your different OS versions. From the documentation:

This module provides a Perl interface to libcurl. It is not intended to be a standalone module and because of this, the main libcurl documentation should be consulted for API details at http://curl.haxx.se. The documentation you're reading right now only contains the Perl specific details, some sample code and the differences between the C API and the Perl one.
The way forward always starts with a minimal test.

In Section Seekers of Perl Wisdom