I don't know if I'm the only one to experience that problem, but in some tutorials, every apostrophe is replaced by something odd like :
...but don’t make it to big...
...it’ll look ugly...
...so it’s up to you...
Check by yourself : http://www.interlopers.net/tutorials/1792
This one for example, is showing the apostrophes perfectly.
Maybe because the page is encoded in UTF-8 ? Something went wrong after a copy-paste ?
Here's a word about it.