I am not able to switch the current Ruby version:
➜ ~ rvm list rvm rubies ruby-1.9.2-p290 [ x86_64 ] ruby-1.9.3-p0 [ x86_64 ] ➜ ~ rvm use ruby-1
You need to change your terminal emulator preferences to allow login shell. Sometimes it is required to use /bin/bash --login as the command.
/bin/bash --login