diff --git a/ext/mysql2/client.c b/ext/mysql2/client.c
index 5bb0fee..68c3efc 100644
--- a/ext/mysql2/client.c
+++ b/ext/mysql2/client.c
@@ -140,6 +140,7 @@ static VALUE nogvl_close(void * ptr) {
   mysql_client_wrapper *wrapper = ptr;
   if (!wrapper->closed) {
     mysql_close(wrapper->client);
+    wrapper->client->net.fd = -1;
     wrapper->closed = 1;
   }
   return Qnil;
diff --git a/lib/mysql2/em.rb b/lib/mysql2/em.rb
index 6d95549..98da1e6 100644
--- a/lib/mysql2/em.rb
+++ b/lib/mysql2/em.rb
@@ -13,12 +13,12 @@ module Mysql2
         end
 
         def notify_readable
+          detach
           begin
             @deferable.succeed(@client.async_result)
           rescue Exception => e
             @deferable.fail(e)
           end
-          detach
         end
       end
 
diff --git a/spec/em/em_spec.rb b/spec/em/em_spec.rb
index ac4f65b..1254c4c 100644
--- a/spec/em/em_spec.rb
+++ b/spec/em/em_spec.rb
@@ -7,7 +7,7 @@ describe Mysql2::EM::Client do
     results = []
     EM.run do
       client1 = Mysql2::EM::Client.new
-      defer1 = client1.query "SELECT sleep(0.05) as first_query"
+      defer1 = client1.query "SELECT sleep(0.1) as first_query"
       defer1.callback do |result|
         results << result.first
         EM.stop_event_loop
@@ -19,8 +19,27 @@ describe Mysql2::EM::Client do
         results << result.first
       end
     end
-    
+
     results[0].keys.should include("second_query")
     results[1].keys.should include("first_query")
   end
+
+  it "should support queries in callbacks" do
+    results = []
+    EM.run do
+      client = Mysql2::EM::Client.new
+      defer1 = client.query "SELECT sleep(0.025) as first_query"
+      defer1.callback do |result|
+        results << result.first
+        defer2 = client.query "SELECT sleep(0.025) as second_query"
+        defer2.callback do |result|
+          results << result.first
+          EM.stop_event_loop
+        end
+      end
+    end
+
+    results[0].keys.should include("first_query")
+    results[1].keys.should include("second_query")
+  end
 end
diff --git a/tasks/compile.rake b/tasks/compile.rake
index 4dae1b2..d46766c 100644
--- a/tasks/compile.rake
+++ b/tasks/compile.rake
@@ -1,9 +1,8 @@
 gem 'rake-compiler', '~> 0.7.1'
 require "rake/extensiontask"
 
-MYSQL_VERSION = "5.1.50"
-MYSQL_MIRROR  = ENV['MYSQL_MIRROR'] || "http://mysql.mirrors.pair.com"
-
+MYSQL_VERSION = "5.1.51"
+MYSQL_MIRROR  = ENV['MYSQL_MIRROR'] || "http://mysql.he.net/"
 
 def gemspec
   @clean_gemspec ||= eval(File.read(File.expand_path('../../mysql2.gemspec', __FILE__)))
@@ -13,15 +12,24 @@ Rake::ExtensionTask.new("mysql2", gemspec) do |ext|
   # reference where the vendored MySQL got extracted
   mysql_lib = File.expand_path(File.join(File.dirname(__FILE__), '..', 'vendor', "mysql-#{MYSQL_VERSION}-win32"))
 
+  # DRY options feed into compile or cross-compile process
+  windows_options = [
+    "--with-mysql-include=#{mysql_lib}/include",
+    "--with-mysql-lib=#{mysql_lib}/lib/opt"
+  ]
+
   # automatically add build options to avoid need of manual input
   if RUBY_PLATFORM =~ /mswin|mingw/ then
-    ext.config_options << "--with-mysql-include=#{mysql_lib}/include"
-    ext.config_options << "--with-mysql-lib=#{mysql_lib}/lib/opt"
+    ext.config_options = windows_options
   else
     ext.cross_compile = true
     ext.cross_platform = ['x86-mingw32', 'x86-mswin32-60']
-    ext.cross_config_options << "--with-mysql-include=#{mysql_lib}/include"
-    ext.cross_config_options << "--with-mysql-lib=#{mysql_lib}/lib/opt"
+    ext.cross_config_options = windows_options
+
+    # inject 1.8/1.9 pure-ruby entry point when cross compiling only
+    ext.cross_compiling do |spec|
+      spec.files << 'lib/mysql2/mysql2.rb'
+    end
   end
 
   ext.lib_dir = File.join 'lib', 'mysql2'
@@ -31,25 +39,16 @@ Rake::ExtensionTask.new("mysql2", gemspec) do |ext|
 end
 Rake::Task[:spec].prerequisites << :compile
 
-namespace :cross do
-  task :file_list do
-    gemspec.extensions = []
-    gemspec.files += Dir["lib/#{gemspec.name}/#{gemspec.name}.rb"]
-    gemspec.files += Dir["lib/#{gemspec.name}/1.{8,9}/#{gemspec.name}.so"]
-    # gemspec.files += Dir["ext/mysql2/*.dll"]
-  end
-end
-
-file 'lib/mysql2/mysql2.rb' do
+file 'lib/mysql2/mysql2.rb' do |t|
   name = gemspec.name
-  File.open("lib/#{name}/#{name}.rb", 'wb') do |f|
+  File.open(t.name, 'wb') do |f|
     f.write <<-eoruby
-require "#{name}/\#{RUBY_VERSION.sub(/\\.\\d+$/, '')}/#{name}"
+RUBY_VERSION =~ /(\\d+.\\d+)/
+require "#{name}/\#{$1}/#{name}"
     eoruby
   end
 end
 
 if Rake::Task.task_defined?(:cross)
   Rake::Task[:cross].prerequisites << "lib/mysql2/mysql2.rb"
-  Rake::Task[:cross].prerequisites << "cross:file_list"
 end