OK... heading down the rabbit hole... The App-Cpan and CPAN modules installed OK from source, but the ExtUtils-MakeMaker had a problem in make test...

...
t/writemakefile_args......ok 1/35Can't locate object method "new" via 
+package "version" at t/writemakefile_args.t line 164.
# Looks like you planned 35 tests but ran 22.
# Looks like your test exited with 2 just after 22.
t/writemakefile_args......dubious                                     
+       
    Test returned status 2 (wstat 512, 0x200)
DIED. FAILED tests 23-35
    Failed 13/35 tests, 62.86% okay
t/xs......................ok                                          
+       
Failed Test            Stat Wstat Total Fail  List of Failed
----------------------------------------------------------------------
+---------
t/writemakefile_args.t    2   512    35   26  23-35
6 tests and 10 subtests skipped.
Failed 1/55 test scripts. 13/760 subtests failed.
Files=55, Tests=760, 17 wallclock secs (11.04 cusr +  3.36 csys = 14.4
+0 CPU)
Failed 1/55 test programs. 13/760 subtests failed.
make: *** [test_dynamic] Error 255
mx:ExtUtils-MakeMaker-6.56
[download]

So I tried running CPAN and then tried, for example, to install 'version' and here's what happened there:

$ sudo cpan
NullLogger: Using logger from Local::Null::Logger
NullLogger: Hooked into output
NullLogger: Patched cargo culting

cpan shell -- CPAN exploration and modules installation (v1.9465)
Enter 'h' for help.

cpan[1]> install version
                                                                      
+                           
CPAN: Storable loaded ok (v2.19)
Going to read '/Users/markhunnibell/.cpan/Metadata'
  Database was generated on Fri, 25 Feb 2011 10:31:13 GMT
Running install for module 'version'
Running make for J/JP/JPEACOCK/version-0.88.tar.gz
CPAN: LWP::UserAgent loaded ok (v5.829)
CPAN: Time::HiRes loaded ok (v1.9715)

  Please, install Net::FTP as soon as possible. CPAN.pm installs it fo
+r you
  if you just type
      install Bundle::libnet

Warning: no success downloading '/Users/markhunnibell/.cpan/sources/au
+thors/id/J/JP/JPEACOCK/version-0.88.tar.gz.tmp17757'. Giving up on it
+.
Fetching with Net::FTP:
ftp://cpan.mirrors.tds.net/pub/CPAN/authors/id/J/JP/JPEACOCK/version-0
+.88.tar.gz
Catching error: "Can't locate object method \"new\" via package \"Net:
+:FTP\" at /opt/local/lib/perl5/5.8.9/CPAN/FTP.pm line 220.\cJ" at /op
+t/local/lib/perl5/5.8.9/CPAN.pm line 391
    CPAN::shell() called at /opt/local/lib/perl5/site_perl/5.8.9/App/C
+pan.pm line 295
    App::Cpan::_process_options('App::Cpan') called at /opt/local/lib/
+perl5/site_perl/5.8.9/App/Cpan.pm line 364
    App::Cpan::run('App::Cpan') called at /opt/local/bin/cpan line 11

cpan[2]> install Bundle::libnet

Fetching with Net::FTP:
ftp://cpan.netnitco.net/pub/mirrors/CPAN/authors/id/G/GB/GBARR/Bundle-
+libnet-1.00.tar.gz
Catching error: "Can't locate object method \"new\" via package \"Net:
+:FTP\" at /opt/local/lib/perl5/5.8.9/CPAN/FTP.pm line 220.\cJ\cI...pr
+opagated at /opt/local/lib/perl5/5.8.9/CPAN/Shell.pm line 1698.\cJ" a
+t /opt/local/lib/perl5/5.8.9/CPAN.pm line 391
    CPAN::shell() called at /opt/local/lib/perl5/site_perl/5.8.9/App/C
+pan.pm line 295
    App::Cpan::_process_options('App::Cpan') called at /opt/local/lib/
+perl5/site_perl/5.8.9/App/Cpan.pm line 364
    App::Cpan::run('App::Cpan') called at /opt/local/bin/cpan line 11
                                                   
cpan[3]> install Net::FTP 
                                    
CPAN: Module::CoreList loaded ok (v2.17)
Net::FTP is up to date (2.77).
[download]

Any other ideas?