I read through the source code for this module... There are at least two bugs I can see where any parameters you pass in the call to "tie" will not be used.

You should contact the author and let him know what is happening.

I think pushing onto a shared array would have to be done like this:

if ($ns->lock()) {
    my $var1 = $ns->getvar('var1');

    push (@$var1, 'another item');
    push (@$var1, 'yet another');

    $ns->setvar('var1', $var1);
    $ns->unlock();
}
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However, that seems to trigger a bug somewhere too.

FWIW, you should be able to use the "reuse => 1" parameter to warn yourself of the problem you were having (creating a new namespace under a different name when you meant to open an existing namespace)