Watir Firefox failure

irb(main):003:0> b = Watir::Browser.new :firefox
Selenium::WebDriver::Error::WebDriverError: unable to obtain stable firefox conn
ection in 60 seconds (127.0.0.1:7055)
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.44.0/lib/s
elenium/webdriver/firefox/launcher.rb:79:in `connect_until_stable'
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.44.0/lib/s
elenium/webdriver/firefox/launcher.rb:37:in `block in launch'
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.44.0/lib/s
elenium/webdriver/firefox/socket_lock.rb:20:in `locked'
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.44.0/lib/s
elenium/webdriver/firefox/launcher.rb:32:in `launch'
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.44.0/lib/s
elenium/webdriver/firefox/bridge.rb:24:in `initialize'
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.44.0/lib/s
elenium/webdriver/common/driver.rb:31:in `new'
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.44.0/lib/s
elenium/webdriver/common/driver.rb:31:in `for'
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/selenium-webdriver-2.44.0/lib/s
elenium/webdriver.rb:67:in `for'
        from c:/Ruby193/lib/ruby/gems/1.9.1/gems/watir-webdriver-0.6.10/lib/wati
r-webdriver/browser.rb:46:in `initialize'
        from (irb):3:in `new'
        from (irb):3
        from c:/Ruby193/bin/irb:12:in `<main>'