Growing up in Mennonite country, I heard a few good mispronunciations. In their defence, the really conservative Mennonites speak German amongst themselves, they don't have radios or televisions, and they keep to themselves as much as possible. Basically, most of what they know either came from reading or from other Mennonites. When they find an unfamiliar word, they sound it out as best they can. The results are kind of interesting when you deal with them as an outsider.
Among other things, I've heard "galaxy" pronounced "ga-LACK-see" and "Croatia" pronounced "Crow-ah-TIE-ah." Both of those were pretty funny after my initial confusion.
The one that annoyed me at times was when they consistently mispronounced the name of the local township. "Woolwich" is named after a place in England, and the second "W" is silent. It's "Wool-itch." Mennonites pronounce it "Wool-witch." When it's one of the Old Orders, I pretty much accept it as part of the accent. But it bugged me when my mainstream Mennonite friends - who went to public school, spoke English primarily, watched TV and dressed like everybody else - also mispronounced it. I got really annoyed with my best friend one time when we were about 25. We were talking about some other name with a silent letter, and I compared it to people saying "Wool-witch." And he says "But it is pronounced Wool-witch."
I must have stared at him for a full 30 seconds before responding to that. Just about cuffed him in the back of the head.
But he ended up marrying somebody from Liverpool a few years later, and she educated him on British names.
