i was having some problems running green shoes on my 64bit linux box,
and eventually those problems were solved.  here is how.  (note: this
is to solve the problems *right now* they will be solved in the next
release of ruby-gtk2)

anyway, the meat & potatoes of the error was this:
`/home/serialhex/.rvm/rubies/ruby-1.9.2-p290/lib/ruby/site_ruby/1.9.1/rubygems/custom_require.rb:36:in
`require': uninitialized constant Gdk::Drawable (NameError)`

go find your gtk2 gem, it's probably in gems/gtk2-1.0.0/ or something
(in my example it tells you very simply).  for me it's at:
`/home/serialhex/.rvm/gems/ruby-1.9.2-p290/gems/gtk2-1.0.0/`

go into the `ext/gtk2` dir in there and open the file `rbgtkinits.c`
in that file, make 2 changes:

take line 240:
 void Init_gtk_inits(void)
 {
     Init_gtk_gdk_gc();    <----- line 240
     ...
 }

and move it to the end:
 void Init_gtk_inits(void)
 {
     ....
     Init_gtk_gdk_gc();   <------ last
 }

then, in that dir (on mine it's
`/home/serialhex/.rvm/gems/ruby-1.9.2-p290/gems/gtk2-1.0.0/ext/gtk2` )
run `make`, drink some water (or coffee, or red bull)

when that is done, copy `gtk2.so` to the `lib` dir:
$ cp gtk2.so ../../lib

then go, and have fun with your gtk or green shoes app :)
hex

-- 
*       𺯯*         
to their level and beat you with experience."
*        What you do today can be automated tomorrow. ~Doug McIlroy