Did you install the gems after installing rc1? Can you post the result of command "gem list"?
*** LOCAL GEMS *** fxri (0.3.6) fxruby (1.6.16) hoe (1.7.0) hpricot (0.6) log4r (1.0.5) ptools (1.1.6) rake (0.8.2) ruby-opengl (0.60.0) rubyforge (1.0.0) sqlite3-ruby (1.2.2) test-unit (2.0.0) win32-api (1.4.3, 1.2.0) win32-clipboard (0.4.4) win32-dir (0.3.2) win32-eventlog (0.5.0) win32-file (0.5.5) win32-file-stat (1.3.1) win32-open3 (0.3.1) win32-process (0.5.9) win32-sapi (0.1.4) win32-sound (0.4.1) windows-api (0.2.4) windows-pr (0.9.3)