I have some builds of fc14 (but on 64bit platform) and the layout is very similar to yours - however I'm not sure how /some/ of the directories got into @INC

I have a combination of the fc14 repo installations with a bunch of CPAN stuff, it appears the CPAN stuff all went into the /usr/local/ directories.

Here are the directories found in @INC which do not exist on disk:

/usr/local/lib64/perl5/site_perl/5.10.0/x86_64-linux-thread-multi
/usr/local/lib/perl5/site_perl/5.10.0
/usr/lib64/perl5/vendor_perl/5.10.0/x86_64-linux-thread-multi
/usr/lib/perl5/vendor_perl
/usr/lib/perl5/site_perl
[download]

I think this may be b/c 64bit is a hybrid system so maybe they include (what would be the standard) 32bit directories in @INC in the global RPM build..

My @INC

 @INC:
    /usr/local/lib64/perl5
    /usr/local/share/perl5
    /usr/lib64/perl5
    /usr/share/perl5
    /usr/lib64/perl5
    /usr/share/perl5
    /usr/local/lib64/perl5/site_perl/5.10.0/x86_64-linux-thread-multi
    /usr/local/lib/perl5/site_perl/5.10.0
    /usr/lib64/perl5/vendor_perl/5.10.0/x86_64-linux-thread-multi
    /usr/lib/perl5/vendor_perl
    /usr/lib/perl5/site_perl
[download]

My perl is:

rpm -q perl
perl-5.12.2-140.fc14.x86_64
[download]

I'm not sure if this is a problem, but someone more experienced in these matters may know better... might be a good question for the Fedora forums

update: Those 5.10.0 directories must be stubs of some kind - I'm not sure how to verify that the modules in the standard distribution were in fact built against the 5.12.2 source code. My distro does include perl5122delta so looking at module versions in there might be one way to start verifying..

also, the 5.10.0 dirs in @INC are found in the config_args strings of the perl build as -Dotherlibdirs