RVM and rails 3.0 beta: rails executable is invalid

after installing

gem install rails --pre

then trying

rails -v

I get the following error

/home/luke/.rvm/gems/ruby-1.8.7-head@rails3pre/gems/activerecord-3.0.0.beta2/lib/rails: Is a directory - /home/luke/.rvm/gems/ruby-1.8.7-head@rails3pre/gems/activerecord-3.0.0.beta2/lib/rails (Errno::EISDIR)
 from /usr/bin/rails:19:in `load'
 from /usr/bin/rails:19

Env details

rvm -v

rvm 0.1.26

gem list

abstract (1.0.0)
actionmailer (3.0.0.beta2)
actionpack (3.0.0.beta2)
activemodel (3.0.0.beta2)
activerecord (3.0.0.beta2)
activeresource (3.0.0.beta2)
activesupport (3.0.0.beta2)
arel (0.3.3)
builder (2.1.2)
bundler (0.9.18)
erubis (2.6.5)
i18n (0.3.6)
mail (2.1.5.3)
memcache-client (1.7.8)
mime-types (1.16)
polyglot (0.3.1)
rack (1.1.0)
rack-mount (0.6.1, 0.4.7)
rack-test (0.5.3)
rails (3.0.0.beta2)
rails3b (3.0.1)
railties (3.0.0.beta2)
rake (0.8.7)
rdoc (2.5.3)
text-format (1.0.0)
text-hyphen (1.0.0)
thor (0.13.4)
treetop (1.4.5)
tzinfo (0.3.19)

Any ideas?

nm, I found it. I had to open a new terminal. I also uninstalled a prior version of rails somewhere along the way, within the same rvm rubie, and might have killed the rails bin file.

I got rid of this error by simply deleting the /var/lib/gems/1.8/bin that appeared in the PATH variable definition in /etc/profile.