It drives me crazy. I say dih-VIH-nohr-um, with both "i"s being short and the accent on the second syllable. No idea.
Come onnnnn Somebody's gotta know. And if everybody knows but me, then somebody's gotta be willing to fill me in.
Erm, but that would be missing out a syllable...... Having studied Latin, i am 99.9% sure it's pronounced as CC says.