I am having some serious problems, however this seems to be a common thing. I have Snow Leopard 10.6.3 and here are my other version info: MySQL mysql Ver 14.14 Distrib 5.1.46, for apple-darwin10.2.0 (i386) using readline 5.1 gem 1.3.6 ruby 1.8.7 (2009-06-08 patchlevel 173) [universal-darwin10.0] My problem is that no matter what I do to try and install the mysql gem, i still get the error every time i do rake db:migrate uninitialized constant MysqlCompat::MysqlRes I have installed the mysql gem based on instructions around the web that say to use export ARCHFLAGS="-arch i386 -arch x86_64" ; sudo gem install --no-rdoc --no-ri mysql -- -v 2.7 --with-mysql-dir=/usr/local --with-mysql-config=/usr/local/mysql/bin/mysql_config This DOES work, as it gives this output: Building native extensions. This could take a while... Successfully installed mysql-2.8.1 1 gem installed Any help would be greatly appreciated