diff --git a/source/net/sourceforge/filebot/MediaTypes.java b/source/net/sourceforge/filebot/MediaTypes.java
index 0c55b6a0..5b8b6f3e 100644
--- a/source/net/sourceforge/filebot/MediaTypes.java
+++ b/source/net/sourceforge/filebot/MediaTypes.java
@@ -6,7 +6,9 @@ import static java.util.Collections.*;
 
 import java.io.FileFilter;
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 import javax.xml.bind.JAXBContext;
 import javax.xml.bind.JAXBException;
@@ -48,6 +50,9 @@ public class MediaTypes {
 	}
 	
 
+	private Map<String, ExtensionFileFilter> filters = synchronizedMap(new HashMap<String, ExtensionFileFilter>());
+	
+
 	public List<String> getExtensionList(String name) {
 		List<String> list = new ArrayList<String>();
 		
@@ -62,7 +67,14 @@ public class MediaTypes {
 	
 
 	public FileFilter getFilter(String name) {
-		return new ExtensionFileFilter(getExtensionList(name));
+		ExtensionFileFilter filter = filters.get(name);
+		
+		if (filter == null) {
+			filter = new ExtensionFileFilter(getExtensionList(name));
+			filters.put(name, filter);
+		}
+		
+		return filter;
 	}
 	
 
diff --git a/source/net/sourceforge/filebot/format/ExpressionFormat.java b/source/net/sourceforge/filebot/format/ExpressionFormat.java
index c3e45dcb..0aff5436 100644
--- a/source/net/sourceforge/filebot/format/ExpressionFormat.java
+++ b/source/net/sourceforge/filebot/format/ExpressionFormat.java
@@ -54,11 +54,9 @@ public class ExpressionFormat extends Format {
 	
 
 	protected ScriptEngine initScriptEngine() throws ScriptException {
-		// use groovy script engine
+		// use Groovy script engine
 		ScriptEngine engine = new GroovyScriptEngineFactory().getScriptEngine();
-		
 		engine.eval(new InputStreamReader(ExpressionFormat.class.getResourceAsStream("ExpressionFormat.lib.groovy")));
-		
 		return engine;
 	}
 	
@@ -159,7 +157,7 @@ public class ExpressionFormat extends Format {
 		
 		// initialize script context with the privileged bindings
 		ScriptContext context = new SimpleScriptContext();
-		context.setBindings(priviledgedBindings, ScriptContext.GLOBAL_SCOPE);
+		context.setBindings(priviledgedBindings, ScriptContext.ENGINE_SCOPE);
 		
 		// reset exception state
 		lastException = null;
diff --git a/source/net/sourceforge/tuned/FileUtilities.java b/source/net/sourceforge/tuned/FileUtilities.java
index 4531c995..6f777d3f 100644
--- a/source/net/sourceforge/tuned/FileUtilities.java
+++ b/source/net/sourceforge/tuned/FileUtilities.java
@@ -73,6 +73,19 @@ public final class FileUtilities {
 	}
 	
 
+	public static String readAll(Reader source) throws IOException {
+		StringBuilder text = new StringBuilder();
+		char[] buffer = new char[2048];
+		
+		int read = 0;
+		while ((read = source.read(buffer)) >= 0) {
+			text.append(buffer, 0, read);
+		}
+		
+		return text.toString();
+	}
+	
+
 	public static void writeFile(ByteBuffer data, File destination) throws IOException {
 		FileChannel fileChannel = new FileOutputStream(destination).getChannel();