Description
If in Settings > Products > Products Settings you specify to use "Orders Currency" (o) "Use active currency" it may cause a problem with displaying currency sign and order amount after order was placed.
 
Solution
Download the updated version of the file:
http://www.viart.com/downloads/order_items-4.0.7.zip
 
Further, extract 'order_items.php' into 'includes' folder via FTP in BINARY mode replacing an existing file. Please do not forget to make a backup copy of the current file in case something goes wrong.