Okay, this could be a horrible suggestion, but stuff like this has worked for me in the past. First off, I'm assuming that you're installing Net::Telnet with

perl -MCPAN -e shell
[download]

and in the shell doing something like

install Net::Telnet
[download]

Now you could just force it with

force install Net::Telnet
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Or if you have a previous library installed, you could try something a tad sketchy by using a backdated version of perl to get it to install. Use perl -v (it'll prolly give you perl 5.6.1), and search your system for perl5.6.0. Try that with the -MCPAN -e shell. That sometimes gets things to install, but you may need to add a use lib line in the beginning of your scripts to get it right.

Hope this helps.
--jay