One app hangs loading Rails and another doesn't; suggest strategy please

When I enter "ruby script/server" in one directory, the result is:

C:\work\ratingasp01>ruby script/server ./script/../config/boot.rb:29:Warning: require_gem is obsolete. Use gem instead. => Booting Mongrel (use 'script/server webrick' to force WEBrick) => Rails application starting on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server ** Starting Mongrel listening at 0.0.0.0:3000 ** Starting Rails with development environment...

The CPU utilization on Ruby hovers at 90% and the Mongrel server is not responsive to a browser.

If I switch to a sister app/directory, the result is:

C:\work\astro1>ruby script/server ./script/../config/boot.rb:28:Warning: require_gem is obsolete. Use gem instead. => Booting Mongrel (use 'script/server webrick' to force WEBrick) => Rails application starting on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server ** Starting Mongrel listening at 0.0.0.0:3000 ** Starting Rails with development environment... ** Rails loaded. ** Loading any Rails specific GemPlugins ** Signals ready. INT => stop (no restart). ** Mongrel available at 0.0.0.0:3000 ** Use CTRL-C to stop.

This version is responsive and uses a tiny amount of CPU.

Looks like Mongrel or Rails is looping. Trying Webrick didn't solve the problem. Please suggest a strategy I can use to determine why I hang in the "Rails loaded." step.

My versions are:

C:\work\ratingasp01>ruby --version ruby 1.8.6 (2007-03-13 patchlevel 0) [i386-mswin32]

C:\work\ratingasp01>rails --version Rails 1.2.3

I'm on Windows XP SP2. Could I be running a different Rails in the "ratingasp01" folder?

Thanks,

Carl