That seems to be a problem on joomla >=1.6 with SEF on.
Please replace the code:
function __construct($config = array(),$skip=false){
parent::__construct($config,$skip);
$this->display[]='update';
if(!$skip){
$this->registerDefaultTask('update');
}
JRequest::setVar('tmpl','component');
}
by:
function __construct($config = array(),$skip=false){
$this->display[]='update';
if(!$skip){
parent::__construct($config,$skip);
$this->registerDefaultTask('update');
}
JRequest::setVar('tmpl','component');
}
in the file components/com_hikashop/controllers/currency.php and try again ?