Hi
I am a South African 1st Ac who has shot in various African countries travelling out of South Africa.
In My experience do the following.
1. Get a letter from the Ugandan consolate in your country stating what and where you are going to shoot.
2. Get you production company tro draw up a carnet... this helps with insurance and any confusion at arrivals and customs.
3. Be as friendly as possible and stay away from "bribes" ( Africans have a huge interest in film making and often will be greatful if you inform them as to what you are doing in their country.
4. Trea ;) t these people with respect, after all its their country.
Regards
Frank