Learningrails.com problem

In that case you are doomed. To use a tutorial that is for a different version of rails will lead to endless problems, you will never know whether a problem you encounter is due to an error you have made or a difference in rails. You must use the right version of rails that the tutorial expects, but you should also use a tutorial that is for rails 3. For example you could try railstutorial.org which is free to use online.