env | grep PERL5LIB

both as userx and as root. I admit up front I don't know anything about perlbrew, but I agree it does sound like a library issue. If you get a certain value for PERL5LIB as userx and nothing as root, I'd try setting PERL5LIB for root to whatever it is you got as userx.

Or alternately, use a 'use lib' statement in scripts owned by root.

/G