When the pronunciation is not intuitive (read: doesn't comply with the usual non-intuitive rules)
You've just been "spoiled" growing up with a phonetically-spelled language.
But, seriously, even native English-speakers will mispronounce non-intuitive words of the types you describe if they're not common conversational terms.
I've been called on mispronouncing English words I've only ever read in books (and never bothered to check the pronunciation with a dictionary - why would I look up the dictionary if the meaning of the word was clear or defined in the text?)
I've always figured that speakers of languages that have gender might find other languages that have gender fairly confusing - I only have to learn what the gender of the word is while you'd have to fight your own idea of what gender it "should have" if the gender is different in their language. I got that to a lesser extent, having been taught, for example, that "table" was feminine in my French classes and having to remember it's masculine in German - but since it's neither in English, I don't have an ingrained idea of its gender that has to be counteracted.
What I like about German, French, Maori, Welsh and Cornish (and other phonetically-spelled languages, but I'm citing ones I've actually learned or tried to learn) is that once you know the rules, you know how to pronounce it and if you hear it clearly, you can spell it. Far less confusing than my own language - like sighting an unfamiliar ~ough word and wondering which of the various pronunciations of that group of letters applies in that case (that one I would look up in a dictionary as "ough" is a known wild-card).
edited 26th Mar '13 1:02:26 AM by Wolf1066