rspec-core: uninitialized constant Test::Unit::TestCase::Assertions (NameError)

Hi there.

I get this error, EVERY time I try run guard or bundle exec rspec or similar…

ive tried googling the error for the past couple of hours and days.

the full error msg:

/home/dg/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/test/unit/testcase.rb:9:in <class:TestCase>': uninitialized constant Test::Unit::TestCase::Assertions (NameError)
from /home/dg/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/test/unit/testcase.rb:8:inmodule:Unit'
from /home/dg/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/test/unit/testcase.rb:4:in <module:Test>'
from /home/dg/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/test/unit/testcase.rb:3:in'
from /home/dg/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/test/unit.rb:5:in <top (required)>'
from /home/dg/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/1.9.1/test/unit/assertions.rb:4:in'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-rails-2.7.0/lib/rspec/rails/adapters.rb:2:in <top (required)>'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-rails-2.7.0/lib/rspec/rails.rb:10:in'
from /home/dg/Projects/advicecapital/spec/spec_helper.rb:4:in <top (required)>'
from /home/dg/Projects/advicecapital/spec/models/user_spec.rb:1:inrequire'
from /home/dg/Projects/advicecapital/spec/models/user_spec.rb:1:in <top (required)>'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-core-2.7.1/lib/rspec/core/configuration.rb:459:inload'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-core-2.7.1/lib/rspec/core/configuration.rb:459:in block in load_spec_files'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-core-2.7.1/lib/rspec/core/configuration.rb:459:inmap'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-core-2.7.1/lib/rspec/core/configuration.rb:459:in load_spec_files'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-core-2.7.1/lib/rspec/core/command_line.rb:18:inrun'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-core-2.7.1/lib/rspec/core/runner.rb:80:in run_in_process'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-core-2.7.1/lib/rspec/core/runner.rb:69:inrun'
from /home/dg/.rvm/gems/ruby-1.9.2-p290/gems/rspec-core-2.7.1/lib/rspec/core/runner.rb:10:in `block in autorun'

thanks in advance