I’m posting this here because I was following the instructions on p36 of the pdf. This could just as well go on the Rails Talk Group or on a Ubuntu list. I’m completely new to Linux, having suffered with Windows for too long. I’ve just installed Ubuntu Hardy Heron on my laptop and I was following the instructions on p36 (to the letter!). All seemed to be going well until I tried reinstalling to Rails v2.02 and updating gem to 1.20. Since then, I’m getting an error - /usr/bin/gem:23: uninitialized constant Gem::GemRunner (NameError) I’ve tried purging and reinstalling to no avail. Is this a problem in the book or have I messed up?