5.8.4, but I think you're right that there is something else involved here.

#! perl -slw
use strict;

package thing;

sub new {
    bless { VALUE => 'YES' }, $_[0];
}

sub value :lvalue {
    my $this = shift;
    $this->{VALUE};
}
package main;

print $];

my $thing = thing->new;

print $thing->value;
$thing->value = undef;
print $thing->value;
__END__
P:\test>junk2
5.008004
YES
Use of uninitialized value in print at P:\test\junk2.pl line 22.
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