The Ruby 1.9 fixes should only apply to 1.9.0 and 1.9.1.

They should never have been applied to 1.9.2 and above because these already include the fixes. Furthermore, the fixes actually break under Ruby 2.0.
Merge pull request #125 from chewi/ruby20-fix

The Ruby 1.9 fixes should only apply to 1.9.0 and 1.9.1.