Ive been poking at this a bit of late: am having troubles getting the @INC setup correctly. If i run your samples as-is Im told that Apache2::Request can't be found. If I add its locale using 'use lib' I get a strange one "Request/Request.so: undefined symbol: Perl_Tstack_sp_ptr"
Apache2::Request is up-to-date on the system. Its not in the @INC though.
I also tried using 'PerlSetEnv PERL5Lib <path>' in httpd.conf to no avail.
EDIT: twiddled the 'use lib' down to one extra path: now I get the same error from a different module:
Starting httpd: /usr/sbin/httpd: symbol lookup error: /usr/lib/perl5/s
+ite_perl/5.8.5/i386-linux-thread-multi/auto/ModPerl/Util/Util.so: und
+efined symbol: Perl_Tstack_sp_ptr