Change the code:
$oldValue = $app->getUserState($this->paramBase.'.list_limit');
if(empty($oldValue)){
$oldValue = $this->params->get('limit');
}
$pageInfo->limit->value = $app->getUserStateFromRequest( $this->paramBase.'.list_limit', 'limit_'.$this->params->get('main_div_name').$category_selected, $this->params->get('limit'), 'int' );
if($oldValue!=$pageInfo->limit->value){
JRequest::setVar('limitstart_'.$this->params->get('main_div_name').$category_selected,0);
}
to:
$pageInfo->limit->value = JRequest::getVar('limitstart_'.$this->params->get('main_div_name').$category_selected,0);
and:
$pageInfo->limit->start = $app->getUserStateFromRequest( $this->paramBase.'.limitstart', 'limitstart_'.$this->params->get('main_div_name').$category_selected, 0, 'int' );
to:
$pageInfo->limit->start = JRequest::getInt('limitstart_'.$this->params->get('main_div_name').$category_selected, 0 );
in the file components/com_hikashop/views/product/view.html.php and that should do what you want.