My order for a Windows 7 desktop wouldn't go through! What happens now?

I have been trying. over the last few days, to order the $329 Windows 7 desktop. Although I successfully (it appeared) placed the item in my cart, the checkout/final order wouldn't go through to completion. I'd thought the problem was with my ISP (Comcast). which has been less than reliable lately, but tonight I discovered my cart had been emptied and the item was "temporarily" out if stock -- so that, apparently, I can't place the order at all -- even though the advertising Dell sent me didn't indicate any supply limits, and pretty much said the offer would be open sometime tomorrow morning.

Given the problems I've had tonight just getting through this website, I now don't think my ISP was the main cause of the problem. I've tried to post this several times, while other websites have responded normally.

Why won't Dell take orders for this product, in accordance with the advertising it sent me? Will I be able to order the product at the advertised price, once it comes back in stock?