"Mispronounced names!"
One my pet peeves about some audio books is a narrator who doesn't bother to learn the pronunciation of names, but just wings it. I am not too far in, but already he calls Murray Gell-Mann "Jel Man" as though he were describing some man made of jelly. Gell is properly pronounced as the 'gel' in the first syllable of gelding, and the vowel in Mann is of the 'ah" variety. This sort of thing REALLY annoys me even although the book itself is quite good.