Did you install DBI.pm ?
Did you install DBD::mysql ?
Did you spell it correctly when you use it?
Have a nice day All decision is left to your taste Update
Well, that was a quick shot and directly in my foot. Well, well. But the error you get indicates that Perl cannot find them along with your old nor your new Perl installation, _as I understand_ there is no problem for Unix to have different versions of Perl running at the same time.