Be sure to select the installed ruby (the part --defaulttells rvm that you want this ruby to be your default ruby version). Sort of:
rvm --default use 1.9.2
This command will also tell you which ruby is currently selected:
rvm list
And hopefully you will see something like:
rvm rubies
ruby-1.9.2-p0 [ x86_64 ]
=> ruby-1.8.7-p302 [ x86_64 ]
, , rvm.
, rvm ruby, ruby gems . , ruby gem ~/.rvm :
which ruby
which gem
!