Error when creating database with a RoR app-Collection of common programming errors

I’m totally new to Rails development, but I had this same problem this week. Eventually, I replaced the line gem 'sqlite-ruby, :require => 'sqlite3' with gem 'sqlite3-ruby', '1.2.5', :require => 'sqlite3' (in the Gemfile)

I had to do this because I’m running Mac OS 10.5.8 rather than 10.6

Maybe that will help.