If anyone has this same problem, I fixed it with this:

/includes/classes/order.php
added
Code:
function getProductId($intProductId) 
	{
		global $db;
		
		$sql = "select products_image from products where products_id = '" .$intProductId. "' limit 1";
		$res = mysql_query($sql);
		
		$row = mysql_fetch_assoc($res);
		//print_r($row);
		return str_replace('-','/',str_replace(array("img_small/", ".JPG"),'',$row['products_image']));
	}
and then around line 800, added it the sql array:

Code:
   $sql_data_array = array('orders_id' => $zf_insert_id,
                              'products_id' => zen_get_prid($this->products[$i]['id']),
                              'products_model' => $this->products[$i]['model'],
                              'products_name' => $this->products[$i]['name'],
                              'products_price' => $this->products[$i]['price'],
                              'final_price' => $this->products[$i]['final_price'],
                              'onetime_charges' => $this->products[$i]['onetime_charges'],
                              'products_tax' => $this->products[$i]['tax'],
                              'products_quantity' => $this->products[$i]['qty'],
                              'products_priced_by_attribute' => $this->products[$i]['products_priced_by_attribute'],
                              'product_is_free' => $this->products[$i]['product_is_free'],
                              'products_discount_type' => $this->products[$i]['products_discount_type'],
							  'product_code' => $this->getProductId($this->products[$i]['id']),
                              'products_discount_type_from' => $this->products[$i]['products_discount_type_from'],
                              'products_prid' => $this->products[$i]['id'])
Hope this helps someone. It seems that FEC does not add the product code to the order table.