OK According to the guy I got the info from it is still working so they are stackable and it does work.
Here is a post from another who did it.
Originally posted by Viking
Okay well it finally took my order as a "backorder" so my credit card won't be charged until they have it in stock. The email they sent me shows the price of $149.99, but when I go to the order status on their website it does show the coupons, but everything including the drive has $0 next to it. Hopefully it will work, if not I can always cancel it.
By the way, thanks for the post! :thumbup