% ./script.pl #!perl -I ~/lib
...both return the error that they can't find the module
Are you *sure* that's the error you're getting? If the above #! line is straight out of your script, you'll be getting a 'command not found' error - which is an entirely different animal.
Assuming you want to use the 5.8.3 you just installed, the #! (shebang) line should read like this:
#!/usr/local/bin/perl
sherm--
