The weakest link currently in the IT world is E Mail. In the past any problems that arose were because the hotel has not received the booking via E Mail (usually it was blocked by a spam filter).
Now in every e mial under the booking details is a link that says 'click on this link to Acknowledge receipt'. if you dont do this you will get the same e mail the next day. If it still isnt confirmed an alert is raised in AccuBook and the hotel is contacted directly.
Note - This is NOT a confirmation that you can take the booking, but rather a confirmation that you have RECEIVED the booking.