When starting my rails server I'm getting an 'uninitialized constant ActionPack' error.

raw stack trace

I'm using blunder with rails 2.3.8

running 'bundle list' shows:

  * actionmailer (2.3.8)
  * actionpack (2.3.8)
  * activerecord (2.3.8)
  * activeresource (2.3.8)
  * activesupport (2.3.8)
  * acts-as-taggable-on (2.0.6)
  * authlogic (2.1.5)
  * builder (2.1.2)
  * cucumber (0.7.3)
  * cucumber-rails (0.3.1)
  * database_cleaner (0.5.2)
  * diff-lcs (1.1.2)
  * faker (0.3.1)
  * gherkin (1.0.30)
  * haml (3.0.7)
  * hoe (2.6.0)
  * json_pure (1.4.3)
  * machinist (1.0.6)
  * nifty-generators (0.4.0)
  * nokogiri (1.4.2)
  * rack (1.1.0)
  * rack-test (0.5.4)
  * rails (2.3.8)
  * rake (0.8.7)
  * rr (0.10.11)
  * rspec (1.3.0)
  * rspec-rails (1.3.2)
  * rubyforge (2.0.4)
  * sqlite3-ruby (1.2.5)
  * term-ansicolor (1.0.5)
  * test-unit (1.2.3)
  * trollop (1.16.2)
  * webrat (0.7.1)

Any idea what's going on here?