Problem with array on ot_tax ? and other problems

[donnerkul]

Is use a php 5 version and array handling seems to be different to version 4. I already had to enter type conversion for the array_merge function, but now on returning from paypal express checkout I get this error:

Warning: reset() [function.reset]: Passed variable is not an array or object in C:\htdocs\http://www.drehmahl.eu\shop\includes...tal\ot_tax.php on line 38

Warning: Variable passed to each() is not an array or object in C:\htdocs\http://www.drehmahl.eu\shop\includes...tal\ot_tax.php on line 39

The problem occures in the process-function:

 function process() {
      global $order, $currencies;

      reset($order->info['tax_groups']);
      while (list($key, $value) = each($order->info['tax_groups'])) {
        if ($value > 0 or STORE_TAX_DISPLAY_STATUS == 1) {
          $this->output[] = array('title' => $key . ':',
                                  'text' => $currencies->format($value, true, $order->info['currency'], $order->info['currency_value']),
                                  'value' => $value);
        }
      }
    }

Any help is very welcome.