Why do I get an error using Nokogiri inside TextMate?

I'm getting a bug in TextMate where I try to use nokogiri 1.4.4 within TextMate, but I get this error:

LoadError: no such file to load — nokogiri

method gem_original_require in custom_require.rb at 开发者_开发问答line 31
method require  in custom_require.rb at line 31
at top level    in getBlocks.rb at line 3

However, if I run the ruby script outside of TextMate it works perfectly fine. Because nokogiri 1.4.4 is in the system!

gem list | grep nokogiri
nokogiri (1.4.4)