The cover up is largely because of the Arab lobby, which is the most powerful in the world.
...bad guys — the Arab supremacist Janjaweed, their backers in the Sudanese government and their protectors in the oil-hungry Chinese government — and good guys, the oppressed African Darfuris... That the Janjaweed are bad guys is beyond doubt — they precipitated a conflict that has killed 200,000 and left 2 million homeless in four years, and their own catalogue of atrocities includes mass murder, wholesale rape and burning of "enemy" villages. The same is true of the Sudanese government, which has instigated and supported the Janjaweed reign of terror, and also of Beijing, which shows ruthless cynicism by shielding Khartoum from international sanction in keeping with its insistence that countries should be left to manage their own internal affairs — a position driven by its desire to protect its oil interests in southern Sudan.
http://www.time.com/time/world/article/0,8599,1667153,00.html
Nigeriaworld Feature Article - On homosexuality: Black ...1 Apr 2009 ... Supremacists include the Ku Klux Klan, Aryan Brotherhood and Arab Janjaweeds. The liberal racist is the direct opposite of the supremacist ...
http://nigeriaworld.com/articles/2009/apr/015.html
The Janjaweed first emerged in 1988 after Chadian President Hissène Habré, backed by France and the United States, defeated the Libyan army, thereby ending Col. Muammar al-Gaddafi's territorial designs on Chad. Libya's Chadian protégé, Acheickh Ibn Omer Saeed, retreated with his Arab militia forces to Darfur, where they were hosted by Sheikh Musa Hilal, the newly-elevated chief of the Mahamid Rizeigat Arabs of north Darfur. Hilal's tribesmen had earlier smuggled Libyan weapons to Ibn Omer's forces. A French-Chadian incursion destroyed Ibn Omer's camp, but his weapons remained with his Mahamid hosts, along with an Arab supremacist ideology associated with the Libyan-sponsored ˜Arab Reunion'.
http://en.allexperts.com/e/j/ja/janjaweed.htm
I wish that were true, but the problem runs deeper. Western journalists (aka leftists) simply don’t want to know and much less print something bad about people darker than themselves. This is the case everywhere, even where the arabs have no influence.
We see the same even in other cases even where muslims are not involved - Zimbabwe etc. There is a wilful ignorance as people in the west prefer to live in a fantasy world rather than deal with reality.