Note that even if you have a libperl.so in /usr/local/lib and none in /usr/lib, you still need to have the library loader look in /usr/local/lib. A few unixes have this configured automatically, but I know of at least one linux distro that doesn't (i.e. RedHat linux).

On linux you have a file /etc/ld.so.conf that contains the directories (beside /lib and /usr/lib) to be searched for libraries. If you have that file and it doesn't contain a /usr/local/lib line, you should probably add it and run ldconfig. On BSD things are probably a bit different. Look for documentation on ld.so and the LD_LIBRARY_PATH environment variable.