What flavor of linux are you using?

This might be a permission issue (chmod). Or if you're running SELinux it could be a security context issue (chcon). I think Fedora comes with this feature on by default, so it's a common "gottcha".

A good sanity check is to try running the cgi script from the command line. If that works, you know that the script runs as *you*, so the problem has to do with running the script as the apache user ('nobody' or 'www-data').

If your distribution provides a package manager for installs, did you use it? Ubuntu (and other Debian variants) have apt-get. RedHat (and variants) have yum. If you use those systems to install things like apache, mysql, etc. then everything should "just work". The only time I've ever had to muck around with LD_LIBRARY_PATH, etc. is when I downloaded tar balls and tried to compile/install "custom" versions of stuff myself. In fact, I even prefer apt-get for installing perl modules over CPAN, especially if the module has a binary component (i.e, things like DBI).