I recently (October 2008) went to Lilongwe, Malawi and back on ZED tickets. I had to use a total of 4 of them, because I had to connect in South Africa both going and coming. I had no trouble using my tickets. In fact, It was really quite painless. Each of the 4 times I presented my tickets, they accepted them with no questions asked, and I was given a seat right at the check-in/ticket counter and didn't even have to wait until I got to the gate. It was almost like having a regular revenue ticket. All in all, everything went very smoothly for me. I don't know about the Congo, but based on my experience in Africa... you should be just fine. Hope that helps.