diff --git a/fml/build.xml b/fml/build.xml
index 0cdc0ff8d..d3088b71a 100644
--- a/fml/build.xml
+++ b/fml/build.xml
@@ -381,23 +381,21 @@
     <signjar alias="FML" jar="${basedir}/target/${universal.jarname}.zip" keypass="${sign.KEYPASS}" keystore="${env.JENKINS_HOME}/${sign.KEYSTORE}" storepass="${sign.STOREPASS}" verbose="true" />
   </target>
   <target name="makebinpatches" depends="buildenvsetup,makeversion">
+    <path id="diffset.libs">
+      <pathelement path="${mcp.home}/jars/libraries/com/google/guava/guava/14.0/guava-14.0.jar"/>
+      <pathelement path="${mcp.home}/jars/libraries/org/ow2/asm/asm-all/4.1/asm-all-4.1.jar"/>
+      <pathelement path="${mcp.home}/jars/libraries/lzma/lzma/0.0.1/lzma-0.0.1.jar"/>
+      <pathelement path="${mcp.obfoutput}/minecraft"/>
+    </path>
     <delete dir="${basedir}/binpatch" verbose="true"/>
-    <java classname="cpw.mods.fml.common.patcher.GenDiffSet">
-      <classpath>
-        <pathelement path="${mcp.obfoutput}/minecraft"/>
-        <fileset dir="${mcp.home}/lib" includes="guava-14.0-rc3.jar,asm-debug-all-4.1.jar"/>
-      </classpath>
+    <java classname="cpw.mods.fml.common.patcher.GenDiffSet" classpathref="diffset.libs">
       <arg path="${mcp.home}/jars/versions/${version.minecraft}/${version.minecraft}.jar.backup"/>
       <arg path="${mcp.obfoutput}/minecraft"/>
       <arg path="${basedir}/deobfuscation_data-${version.minecraft}.lzma"/>
       <arg path="${basedir}/binpatch/client"/>
       <arg value="false"/>
     </java>
-    <java classname="cpw.mods.fml.common.patcher.GenDiffSet">
-      <classpath>
-        <pathelement path="${mcp.obfoutput}/minecraft"/>
-        <fileset dir="${mcp.home}/lib" includes="guava-14.0-rc3.jar,asm-debug-all-4.1.jar"/>
-      </classpath>
+    <java classname="cpw.mods.fml.common.patcher.GenDiffSet"  classpathref="diffset.libs">
       <arg path="${mcp.home}/jars/minecraft_server.${version.minecraft}.jar.backup"/>
       <arg path="${mcp.obfoutput}/minecraft"/>
       <arg path="${basedir}/deobfuscation_data-${version.minecraft}.lzma"/>
diff --git a/fml/client/cpw/mods/fml/client/GuiCustomModLoadingErrorScreen.java b/fml/client/cpw/mods/fml/client/GuiCustomModLoadingErrorScreen.java
index 8212e0425..fbd8b20a9 100644
--- a/fml/client/cpw/mods/fml/client/GuiCustomModLoadingErrorScreen.java
+++ b/fml/client/cpw/mods/fml/client/GuiCustomModLoadingErrorScreen.java
@@ -5,7 +5,7 @@
  * are made available under the terms of the GNU Lesser Public License v2.1
  * which accompanies this distribution, and is available at
  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
- * 
+ *
  * Contributors:
  *     cpw - implementation
  */
@@ -21,6 +21,7 @@ public class GuiCustomModLoadingErrorScreen extends GuiErrorScreen
     private CustomModLoadingErrorDisplayException customException;
     public GuiCustomModLoadingErrorScreen(CustomModLoadingErrorDisplayException customException)
     {
+        super(null,null);
         this.customException = customException;
     }
     @Override
diff --git a/fml/client/cpw/mods/fml/client/GuiDupesFound.java b/fml/client/cpw/mods/fml/client/GuiDupesFound.java
index 7345bc76f..2fbf17b4b 100644
--- a/fml/client/cpw/mods/fml/client/GuiDupesFound.java
+++ b/fml/client/cpw/mods/fml/client/GuiDupesFound.java
@@ -5,7 +5,7 @@
  * are made available under the terms of the GNU Lesser Public License v2.1
  * which accompanies this distribution, and is available at
  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
- * 
+ *
  * Contributors:
  *     cpw - implementation
  */
@@ -29,6 +29,7 @@ public class GuiDupesFound extends GuiErrorScreen
 
     public GuiDupesFound(DuplicateModsFoundException dupes)
     {
+        super(null,null);
         this.dupes = dupes;
     }
 
diff --git a/fml/client/cpw/mods/fml/client/GuiModsMissing.java b/fml/client/cpw/mods/fml/client/GuiModsMissing.java
index 0597ebb94..04e67147b 100644
--- a/fml/client/cpw/mods/fml/client/GuiModsMissing.java
+++ b/fml/client/cpw/mods/fml/client/GuiModsMissing.java
@@ -24,6 +24,7 @@ public class GuiModsMissing extends GuiErrorScreen
 
     public GuiModsMissing(MissingModsException modsMissing)
     {
+        super(null,null);
         this.modsMissing = modsMissing;
     }
 
diff --git a/fml/client/cpw/mods/fml/client/GuiWrongMinecraft.java b/fml/client/cpw/mods/fml/client/GuiWrongMinecraft.java
index ff20808cc..6d87027db 100644
--- a/fml/client/cpw/mods/fml/client/GuiWrongMinecraft.java
+++ b/fml/client/cpw/mods/fml/client/GuiWrongMinecraft.java
@@ -5,7 +5,7 @@
  * are made available under the terms of the GNU Lesser Public License v2.1
  * which accompanies this distribution, and is available at
  * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
- * 
+ *
  * Contributors:
  *     cpw - implementation
  */
@@ -22,6 +22,7 @@ public class GuiWrongMinecraft extends GuiErrorScreen
     private WrongMinecraftVersionException wrongMC;
     public GuiWrongMinecraft(WrongMinecraftVersionException wrongMC)
     {
+        super(null,null);
         this.wrongMC = wrongMC;
     }
     @Override
diff --git a/fml/common/cpw/mods/fml/common/patcher/GenDiffSet.java b/fml/common/cpw/mods/fml/common/patcher/GenDiffSet.java
index 96dcd6516..410b58768 100644
--- a/fml/common/cpw/mods/fml/common/patcher/GenDiffSet.java
+++ b/fml/common/cpw/mods/fml/common/patcher/GenDiffSet.java
@@ -2,7 +2,10 @@ package cpw.mods.fml.common.patcher;
 
 import java.io.File;
 import java.io.IOException;
+import java.util.Arrays;
 import java.util.Collections;
+import java.util.List;
+import java.util.Locale;
 import java.util.jar.JarEntry;
 import java.util.jar.JarFile;
 import java.util.logging.Level;
@@ -19,11 +22,13 @@ import cpw.mods.fml.repackage.com.nothome.delta.Delta;
 
 public class GenDiffSet {
 
+    private static final List<String> RESERVED_NAMES = Arrays.asList("CON", "PRN", "AUX", "NUL", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7", "COM8", "COM9", "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9");
+
     public static void main(String[] args) throws IOException
     {
         String sourceJar = args[0]; //Clean Vanilla jar minecraft.jar or minecraft_server.jar
         String targetDir = args[1]; //Directory containing obfed output classes, typically mcp/reobf/minecraft
-        String deobfData = args[2]; //Path to FML's deobfusication_data.zip
+        String deobfData = args[2]; //Path to FML's deobfusication_data.lzma
         String outputDir = args[3]; //Path to place generated .binpatch
         String killTarget = args[4]; //"true" if we should destroy the target file if it generated a successful .binpatch
 
@@ -40,12 +45,19 @@ public class GenDiffSet {
         for (String name : remapper.getObfedClasses())
         {
 //            Logger.getLogger("GENDIFF").info(String.format("Evaluating path for data :%s",name));
-            File targetFile = new File(targetDir, name.replace('/', File.separatorChar) + ".class");
+            String fileName = name;
+            String jarName = name;
+            if (RESERVED_NAMES.contains(name.toUpperCase(Locale.ENGLISH)))
+            {
+                fileName = "_"+name;
+            }
+            File targetFile = new File(targetDir, fileName.replace('/', File.separatorChar) + ".class");
+            jarName = jarName+".class";
             if (targetFile.exists())
             {
                 String sourceClassName = name.replace('/', '.');
                 String targetClassName = remapper.map(name).replace('/', '.');
-                JarEntry entry = sourceZip.getJarEntry(name);
+                JarEntry entry = sourceZip.getJarEntry(jarName);
 
                 byte[] vanillaBytes = entry != null ? ByteStreams.toByteArray(sourceZip.getInputStream(entry)) : new byte[0];
                 byte[] patchedBytes = Files.toByteArray(targetFile);
diff --git a/fml/patches/minecraft/net/minecraft/client/gui/GuiErrorScreen.java.patch b/fml/patches/minecraft/net/minecraft/client/gui/GuiErrorScreen.java.patch
deleted file mode 100644
index ed520448b..000000000
--- a/fml/patches/minecraft/net/minecraft/client/gui/GuiErrorScreen.java.patch
+++ /dev/null
@@ -1,11 +0,0 @@
---- ../src-base/minecraft/net/minecraft/client/gui/GuiErrorScreen.java
-+++ ../src-work/minecraft/net/minecraft/client/gui/GuiErrorScreen.java
-@@ -22,6 +22,8 @@
-         this.field_73887_h.add(new GuiButton(0, this.field_73880_f / 2 - 100, 140, I18n.func_135053_a("gui.cancel")));
-     }
- 
-+    public GuiErrorScreen(){}
-+
-     public void func_73863_a(int p_73863_1_, int p_73863_2_, float p_73863_3_)
-     {
-         this.func_73733_a(0, 0, this.field_73880_f, this.field_73881_g, -12574688, -11530224);