Due to the complex way in which availability is calculated and released, the mere fact that seats are available on each segment of your planned itinerary does not mean that they are available on the itinerary as a whole. E.g. MAN-FRA: wide open; FRA-ORD: wide open; MAN-FRA on a MAN-FRA-ORD: nothing. In such circumstances the ICC may or may not be able to book it for you.
