the original code in item.php was:

<a title="<?php echo htmlentities($attachment->titleAttribute, ENT_QUOTES, 'UTF-8'); ?>" href="<?php echo JRoute::_('index.php?option=com_k2&view=item&task=download&id='.$attachment->id); ?>"> 

i replaced that with:

<a title="<?php echo htmlentities($attachment->titleAttribute, ENT_QUOTES, 'UTF-8'); ?>" href="<?php echo htmlentities($attachment->titleAttribute, ENT_QUOTES, 'UTF-8'); ?>">