I have done some more research, and have seem to narrowed down the issue.

This file
app/design/frontend/sns_toronto/default/template/bundle/catalog/product/price.phtml

on line 112-114 we have this:
<?php if ($_taxHelper->displayPriceIncludingTax()): ?>
<?php echo $_coreHelper->currency($_minimalPriceInclTax) ?>
<?php else: ?>

.. is here we have a problem.

$_coreHelper->currency($_minimalPriceInclTax) does not return the correct value including tax on category pages.

Why? 🙁

Rgds, Martin