Hmm yes, quite right :-( Do you happen to have a 5.6.0 kicking about? I assume that this problem only appeared in 5.6.1, but I'm not sure. It would be nice to know.
It's tempting just to change the version test to
if ($] < 5.006001)
or something, but that doesn't really go to the root of the
problem...
.robin.
