http://www.perlmonks.org?node_id=888529


in reply to Re^2: @INC site/lib problem on Windows 7 and XP (ActiveState Perl)
in thread @INC site/lib problem on Windows 7 and XP (ActiveState Perl)

There is a bug in core Perl on Windows that doesn't set up @INC correctly if Perl is installed into a directory that starts with the letter '5'. Your problem should go away if you install into C:/activestate/perl/v5.10 instead.

This bug is at least 10 years old and somewhat related to finding additional site_lib directories when you are using the versioned directory layout scheme where multiple Perl versions share site_lib directories.