in reply to Help in installing DBD::Oracle module
You could trace what perl is doing under the hood. Something like
$ strace -efile perl -MDBI=1.51 -e1 2>&1 | grep DBI
This might give you a clearer picture of where it's actually looking, and what problem it's having with your private directory...
(BTW, that space in your paths is a cut-n-paste error, is it?)
In Section Seekers of Perl Wisdom