As dectected in the fuel supply by W.C. Fields. The term "Ubangi" denotes a black person. Taken altogether, the somewhat-famous Fields quote simply indicates something out of place or awry, some evil intent. Fields wrote in the 20's and 30's, so those people in positions of social power then didn't necessarily consider this offensive.
"I detect a Ubangi in the fuel supply." -W.C. Fields
by SuperFly2905 November 24, 2005
Just to clarify the above reference....."Ubangi in the fuel supply" was a paraphrase of the expression "nigger in the woodpile" which was too offensive even in W.C. Fields' time.
Ubangi, also a river in Africa
by coolsuds August 25, 2006