Hi,
If you're just after a rough hack, and if /usr/local/lib/perl5/site_perl/5.8.8/i686-linux is empty and /usr/local/lib/perl5/site_perl/5.8.8 contains only the (empty) i686-linux directory, then you could rename the /usr/local/lib/perl5/site_perl/5.8.8 directory (to hide it from the system), and then rename /usr/local/lib/perl5/site_perl/5.8.0 to /usr/local/lib/perl5/site_perl/5.8.8.

But, if there are already files in /usr/local/lib/perl5/site_perl/5.8.8 then you might lose something you want.

I personally build from source on Mandrake Linux (also 9.1) - if you had done the same then /usr/local/lib/perl5/site_perl/5.8.0/i686-linux and /usr/local/lib/perl5/site_perl/5.8.0 would have been added to @INC and there would be no problem. I would have thought the same could be done with rpm packages - but I don't have any experience of them wrt perl.

Cheers,
Rob