Although this is an ancient posting, I think that it may still be a problem for some people today...

my $.10: If perldoc is run as root, it will try to drop priviliges - by changing UID to nobody or -2, normally this means that the perl-libraries (at least lib/Pod/...) and the documentation root is likely to read, must be public readable...

That would explain the diagnostics, but the sollution may vary, here are some suggestions on howto read perldoc perldoc:

• su $LOGNAME perldoc perldoc
• chmod -R a+rX /perl-install-tree; perldoc perldoc
• man perldoc

you are like to have several others solutions/workarounds