For all those having problems with CPAN module installs, there is one (rather odd) solution that has worked for me.

Log in as root

$ su -
# cd ~/.cpan/build

If this gives you an error, try changing instead to the home directory of the user that did the install: # cd /home/myusername/.cpan/build

# ls -l

Change to the directory of the package in question (using ZOOM as an example, the directory name should be similar but will be different)

# cd Net-Z3950-ZOOM-1.21-s1Kt5N
# make
# make install

In many cases, doing this when the cpan tool absolutely refused to work helped enormously.

Good luck to you all,
--
Jesse