I'm a native English speaker, but I sometimes have a problem with pronouncing words that I've read but either not heard spoken, or heard but didn't realize it was the same word. I'll make up a pronunciation in my head and then use that in conversation and confuse whoever I'm talking to.

My wife catches me saying a new one every month or two, and she thinks its hilarious (but she also helps me pronounce it correctly, so I can't complain too much.)