Windows7 DW CS4 - eCart 4.5.2. Opening up say the cart.php page or any other page in the PWS that has the cart object. Double-clicking on the eCart Object (WA_Store_Cart) in Server Behaviors. Going to shipping and adding in a 4th shipping item. No error during any changes, or just adding in "Free Shipping" to the list until the changes are being saved with the OK button.