I'm unable to even "require 'mongo'" with mongo-1.10.0 on JRuby.

Steps to reproduce:
1. Switch to JRuby (I used version 1.7.11)
2. Install mongo-1.10.0 (gem install mongo -v 1.10.0)
3. Open irb
4. At the irb prompt: require 'rubygems'; require 'mongo'

Expected results:
Gem should load without errors.

Actual results:
I get the following error:

LoadError: no such file to load – /Users/ben/.gem/jruby/1.9.3/gems/mongo-1.10.0/ext/jsasl/target/jsasl
from org/jruby/RubyKernel.java:1085:in `require'
from /Users/ben/.rubies/jruby-1.7.11/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/ben/.rubies/jruby-1.7.11/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:53:in `require'
from /Users/ben/.gem/jruby/1.9.3/gems/mongo-1.10.0/lib/mongo/functional/sasl_java.rb:20:in `(root)'
from org/jruby/RubyKernel.java:1085:in `require'
from /Users/ben/.rubies/jruby-1.7.11/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/ben/.rubies/jruby-1.7.11/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:53:in `require'
from /Users/ben/.gem/jruby/1.9.3/gems/mongo-1.10.0/lib/mongo/functional.rb:1:in `(root)'
from org/jruby/RubyKernel.java:1085:in `require'
from /Users/ben/.rubies/jruby-1.7.11/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:55:in `require'
from /Users/ben/.rubies/jruby-1.7.11/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:53:in `require'
from /Users/ben/.gem/jruby/1.9.3/gems/mongo-1.10.0/lib/mongo/functional.rb:21:in `(root)'
from org/jruby/RubyKernel.java:1085:in `require'
from /Users/ben/.gem/jruby/1.9.3/gems/mongo-1.10.0/lib/mongo.rb:1:in `(root)'
from /Users/ben/.gem/jruby/1.9.3/gems/mongo-1.10.0/lib/mongo.rb:78:in `(root)'
from org/jruby/RubyKernel.java:1121:in `eval'
from /Users/ben/.rubies/jruby-1.7.11/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:1:in `(root)'
from /Users/ben/.rubies/jruby-1.7.11/lib/ruby/shared/rubygems/core_ext/kernel_require.rb:135:in `require'
from (irb):2:in `evaluate'
from org/jruby/RubyKernel.java:1521:in `loop'
from org/jruby/RubyKernel.java:1284:in `catch'
from org/jruby/RubyKernel.java:1284:in `catch'

This example is from a machine running Mac OS X, but I've seen the same error on Linux as well.