yeah if something is backordered it's usually pretty standard operating procedure to let them know that it's back ordered and if they want it they'll put the order in for it and let them know it's there just for a later ship date and generally collect payment, but not charge and then tell the customer it's back ordered.
There are some shops that will do this. It's there dirty trick of saying "Well, we got your money now there for you will not shop elsewhere"
The only time I do that is if it's a special order item. And there is 2 types of special order items
1. Special Order - We normally don't stock/sell it, but I get it in with in a few days from the distributor. This is typcial of any weird items.
2. Very Special Order - National Distributor normally does not have this stock item in either and needs to order it in from over sea. And normally they want payment in full upfont. Typically spare parts or extremely high end Quadro Graphics cards.
However i would find this behavour very strange from the manufacturer as you are buying directly from the manufacturer.