I have noticed that C Trip is using wholesale agencies to book Hotel rooms for their prepaid bookings instead of booking direct with hotels. These agencies do not have direct connectivity with hotels (unlike c trip, who do) and need to make their bookings the old fashioned way, often by fax. This causes a delay in confirming the room, and if they have filled their allotment at the hotel, or the room type is sold out, they may need to book a higher rate. This may explain some of the issues some of you have experienced.