I'm a bit confused. Here what I've understood: there's a CGI script that has some problems, so you tried it from the command line, where it gives compilation errors due to lack of LWP::UserAgent. My suspect is that you have two version of Perl on that machine. One is /usr/bin/perl, which is used by the script when run through the webserver, and the other one is /usr/local/bin/perl, which is being called when you type perl from the command line. The latter has not LWP::UserAgent installed. You can verify my suspect typing:
in reply to Can't locate LWP/UserAgent.pm
at the command prompt.