Please take care of your PATH variable, I had to remove also all ruby and rvm entries from .bashrc, .profile and .bash_profile. Maybe somewhere there your old ruby is specified.
Additionally: On my MACOSX_10.6.8 I just had problems updating ruby-1.9.3p125 to the newest version. So I did everything from scratch and removed (rvm remove 1.9.3p125) and also did rvm implode to remove the ~/.rvm directory completely.
Check How can I remove RVM (Ruby Version Manager) from my system?
Later on:
- curl -L https://get.rvm.io | bash -s stable
- source ~/.rvm/scripts/rvm
- rvm install 1.9.3
After doing that, everything worked just fine!