OK, I have an iPhone 4 with iOS 5.1 - restored to factory and dictionary reset... and it STILL autocorrects "if" to "of" (and vice versa), as well as "so" <--> "do". Can somebody please tell me what file on the iPhone is causing this to happen? I really want to modify it. I have iFile installed and ready to go, but am having trouble determining what to do in order to fix it. 90% of the time when it autocorrects those words, it does so incorrectly. I can't believe such a simple bug STILL isn't fixed, even with the latest iOS release.