diff --git a/pdex/Todo, GSoC 2013.txt b/pdex/Todo, GSoC 2013.txt
index 4c8abef07..56d855234 100644
--- a/pdex/Todo, GSoC 2013.txt	
+++ b/pdex/Todo, GSoC 2013.txt	
@@ -126,6 +126,19 @@ x Working for local code
 * Labels for predefined class objects
 * Chaining support for labels
 
+Synchronization 
+===============
+
+Gotta do it carefully between main thread, ECS Thread, and SwingWorker threads
+Fields that are concurrently accessed:
+
+ECS members:
+ArrayList<Problem> problems - updated in ECS, accessed by ErrorBar.update()
+ArrayList<URL> classpathJars - updated in ECS, accessed by ASTGenerator.loadJars()
+hasErrors, syntaxErrors - Atomic Boolean
+CompilationUnit cu - updated in ECS, accessed a zillion times in ASTGenerator :'( 
+
+
 General Stuff
 =============
 
diff --git a/pdex/src/processing/mode/experimental/ErrorBar.java b/pdex/src/processing/mode/experimental/ErrorBar.java
index 7c3d701cc..34c75904a 100755
--- a/pdex/src/processing/mode/experimental/ErrorBar.java
+++ b/pdex/src/processing/mode/experimental/ErrorBar.java
@@ -174,21 +174,22 @@ public class ErrorBar extends JPanel {
         // Each problem.getSourceLine() will have an extra line added
         // because of
         // class declaration in the beginning as well as default imports
-        for (Problem problem : problems) {
-          if (problem.getTabIndex() == currentTab) {
-            // Ratio of error line to total lines
-            float y = (problem.getLineNumber() - errorCheckerService.defaultImportsOffset)
-                / ((float) totalLines);
-            // Ratio multiplied by height of the error bar
-            y *= fheight - 15; // -15 is just a vertical offset
-            errorPoints
-                .add(new ErrorMarker(problem, (int) y,
-                                     problem.isError() ? ErrorMarker.Error
-                                         : ErrorMarker.Warning));
-            // System.out.println("Y: " + y);
+        synchronized (problems) {
+          for (Problem problem : problems) {
+            if (problem.getTabIndex() == currentTab) {
+              // Ratio of error line to total lines
+              float y = (problem.getLineNumber() - errorCheckerService.defaultImportsOffset)
+                  / ((float) totalLines);
+              // Ratio multiplied by height of the error bar
+              y *= fheight - 15; // -15 is just a vertical offset
+              errorPoints
+                  .add(new ErrorMarker(problem, (int) y,
+                                       problem.isError() ? ErrorMarker.Error
+                                           : ErrorMarker.Warning));
+              // System.out.println("Y: " + y);
+            }
           }
         }
-
         return null;
       }
 
diff --git a/pdex/src/processing/mode/experimental/ErrorCheckerService.java b/pdex/src/processing/mode/experimental/ErrorCheckerService.java
index 55de1db99..9716c160f 100644
--- a/pdex/src/processing/mode/experimental/ErrorCheckerService.java
+++ b/pdex/src/processing/mode/experimental/ErrorCheckerService.java
@@ -510,51 +510,52 @@ public class ErrorCheckerService implements Runnable{
       if (errorList == null) {
         return;
       }
-
-      problems = new DefaultProblem[errorList.length];
-
-      for (int i = 0; i < errorList.length; i++) {
-
-        // for (int j = 0; j < errorList[i].length; j++)
-        // System.out.print(errorList[i][j] + ", ");
-
-        problems[i] = new DefaultProblem((char[]) errorList[i][0],
-            (String) errorList[i][1],
-            ((Integer) errorList[i][2]).intValue(),
-            (String[]) errorList[i][3],
-            ((Integer) errorList[i][4]).intValue(),
-            ((Integer) errorList[i][5]).intValue(),
-            ((Integer) errorList[i][6]).intValue(),
-            ((Integer) errorList[i][7]).intValue(), 0);
-
-        // System.out
-        // .println("ECS: " + problems[i].getMessage() + ","
-        // + problems[i].isError() + ","
-        // + problems[i].isWarning());
-
-        IProblem problem = problems[i];
-//        log(problem.getMessage());
-//        for (String j : problem.getArguments()) {
-//          log("arg " + j);
-//        }
-        int a[] = calculateTabIndexAndLineNumber(problem);
-        Problem p = new Problem(problem, a[0], a[1]);
-        if ((Boolean) errorList[i][8]) {
-          p.setType(Problem.ERROR);
-          containsErrors.set(true); // set flag
+      
+      synchronized (problemsList) {
+        problems = new DefaultProblem[errorList.length];
+  
+        for (int i = 0; i < errorList.length; i++) {
+  
+          // for (int j = 0; j < errorList[i].length; j++)
+          // System.out.print(errorList[i][j] + ", ");
+  
+          problems[i] = new DefaultProblem((char[]) errorList[i][0],
+              (String) errorList[i][1],
+              ((Integer) errorList[i][2]).intValue(),
+              (String[]) errorList[i][3],
+              ((Integer) errorList[i][4]).intValue(),
+              ((Integer) errorList[i][5]).intValue(),
+              ((Integer) errorList[i][6]).intValue(),
+              ((Integer) errorList[i][7]).intValue(), 0);
+  
+          // System.out
+          // .println("ECS: " + problems[i].getMessage() + ","
+          // + problems[i].isError() + ","
+          // + problems[i].isWarning());
+  
+          IProblem problem = problems[i];
+  //        log(problem.getMessage());
+  //        for (String j : problem.getArguments()) {
+  //          log("arg " + j);
+  //        }
+          int a[] = calculateTabIndexAndLineNumber(problem);
+          Problem p = new Problem(problem, a[0], a[1]);
+          if ((Boolean) errorList[i][8]) {
+            p.setType(Problem.ERROR);
+            containsErrors.set(true); // set flag
+          }
+          
+          if ((Boolean) errorList[i][9]) {
+            p.setType(Problem.WARNING);
+          }
+  
+          // If warnings are disabled, skip 'em
+          if (p.isWarning() && !warningsEnabled) {
+            continue;
+          }
+          problemsList.add(p);
         }
-        
-        if ((Boolean) errorList[i][9]) {
-          p.setType(Problem.WARNING);
-        }
-
-        // If warnings are disabled, skip 'em
-        if (p.isWarning() && !warningsEnabled) {
-          continue;
-        }
-        problemsList.add(p);
       }
-
     } catch (ClassNotFoundException e) {
       System.err.println("Compiltation Checker files couldn't be found! "
           + e + " compileCheck() problem.");
@@ -717,7 +718,7 @@ public class ErrorCheckerService implements Runnable{
   /**
    * Enable/Disable warnings from being shown
    */
-  public boolean warningsEnabled = true;
+  volatile public boolean warningsEnabled = true;
 
   /**
    * Sets compiler options for JDT Compiler
@@ -747,7 +748,7 @@ public class ErrorCheckerService implements Runnable{
   /**
    * Updates the error table in the Error Window.
    */
-  synchronized public void updateErrorTable() {
+  public void updateErrorTable() {
 
     try {
       String[][] errorData = new String[problemsList.size()][3];
diff --git a/pdex/src/processing/mode/experimental/ExperimentalMode.java b/pdex/src/processing/mode/experimental/ExperimentalMode.java
index db5f793b6..d5f07395a 100755
--- a/pdex/src/processing/mode/experimental/ExperimentalMode.java
+++ b/pdex/src/processing/mode/experimental/ExperimentalMode.java
@@ -46,7 +46,7 @@ public class ExperimentalMode extends JavaMode {
   public static final boolean VERBOSE_LOGGING = true;
   //public static final boolean VERBOSE_LOGGING = false;  
   public static final int LOG_SIZE = 512 * 1024; // max log file size (in bytes)
-  public static boolean DEBUG = !true;
+  public static boolean DEBUG = true;
   
   public ExperimentalMode(Base base, File folder) {
     super(base, folder);