Just for a bit more explanation: modules need to be built against the version of perl they're being used with to make sure the internals and other APIs used match up with each other. You should be able to use modules with the same major.minor irrespective of the patch level, but otherwise they're going to be incompatible. If you (say) have a personal library directory with local::lib that you built with a previous version and then upgrade (again, to a different major.minor) you should reinstall things as you say you did (and/or make a different directory for that version and install things there).