I have installed Ruby 1.6.4 and ruby-gtk 0.25 from FreeBSD's Ports system 
on FreeBSD 4.3-STABLE, and I'm having trouble getting scripts that use this 
module working.

The ruby-gtk port installed the example scripts in 
/usr/local/share/examples/ruby/gtk.  These scripts run fine (eg. "ruby 
text.rb"), but simple scripts I have written, even just "require 'gtk'", 
fail with the error:
../gtk.rb:3: uninitialized constant Gtk (NameError)
        from gtk.rb:1:in `require'
        from gtk.rb:1

If I copy the examples from /usr/local/share/examples/ruby/gtk into my home 
directory, they fail to work there too.  Has anyone else encountered this 
problem, or does anyone with more Ruby knowledge know what I should do to 
find out why this is happening?

Thanks,
Tom