Hi, we spent a while in in Goma and Bukavu, DRC in 2010, I would be very dubious about camping, we had no problems at all while we were there. But things can go wrong very quickly. To put this in context, many NGOs do not allow their staff to move around those two towns unless they are in a vehicle. Your choice but I feel this is a part of the world where you really need to have things properly planned out and some decent security overnight.
On the flip side, while we didn't camp in Uganda, I don't think there would have been any problem at all if we'd wanted to, as long as you stick to proper camp sites I think it would be fine. As others have mentioned, though, you can get pretty cheap accommodation.......
pkh