diff --git a/src/com/android/exchange/SyncManager.java b/src/com/android/exchange/SyncManager.java
index 3defdc5e3..c096c5077 100644
--- a/src/com/android/exchange/SyncManager.java
+++ b/src/com/android/exchange/SyncManager.java
@@ -69,21 +69,21 @@ import android.database.ContentObserver;
 import android.database.Cursor;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
-import android.net.Uri;
 import android.net.NetworkInfo.State;
+import android.net.Uri;
 import android.os.Bundle;
 import android.os.Debug;
 import android.os.Handler;
 import android.os.IBinder;
 import android.os.PowerManager;
+import android.os.PowerManager.WakeLock;
 import android.os.Process;
 import android.os.RemoteCallbackList;
 import android.os.RemoteException;
-import android.os.PowerManager.WakeLock;
 import android.provider.Calendar;
-import android.provider.ContactsContract;
 import android.provider.Calendar.Calendars;
 import android.provider.Calendar.Events;
+import android.provider.ContactsContract;
 import android.util.Log;
 
 import java.io.BufferedReader;
@@ -95,6 +95,7 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
+import java.util.concurrent.ConcurrentHashMap;
 
 /**
  * The SyncManager handles all aspects of starting, maintaining, and stopping the various sync
@@ -210,8 +211,9 @@ public class SyncManager extends Service implements Runnable {
     private Object mStatusChangeListener;
     private EasAccountsUpdatedListener mAccountsUpdatedListener;
 
-    private HashMap<Long, CalendarObserver> mCalendarObservers =
-        new HashMap<Long, CalendarObserver>();
+    // Concurrent because CalendarSyncAdapter can modify the map during a wipe
+    private ConcurrentHashMap<Long, CalendarObserver> mCalendarObservers =
+        new ConcurrentHashMap<Long, CalendarObserver>();
 
     private ContentResolver mResolver;
 
@@ -659,11 +661,14 @@ public class SyncManager extends Service implements Runnable {
     /**
      * Unregister all CalendarObserver's
      */
-    private void unregisterCalendarObservers() {
-        for (CalendarObserver observer: mCalendarObservers.values()) {
-            mResolver.unregisterContentObserver(observer);
+    static public void unregisterCalendarObservers() {
+        SyncManager syncManager = INSTANCE;
+        if (syncManager == null) return;
+        ContentResolver resolver = syncManager.mResolver;
+        for (CalendarObserver observer: syncManager.mCalendarObservers.values()) {
+            resolver.unregisterContentObserver(observer);
         }
-        mCalendarObservers.clear();
+        syncManager.mCalendarObservers.clear();
     }
 
     /**
diff --git a/src/com/android/exchange/adapter/CalendarSyncAdapter.java b/src/com/android/exchange/adapter/CalendarSyncAdapter.java
index 317f22576..97074cabc 100644
--- a/src/com/android/exchange/adapter/CalendarSyncAdapter.java
+++ b/src/com/android/exchange/adapter/CalendarSyncAdapter.java
@@ -25,6 +25,7 @@ import com.android.email.provider.EmailContent.Message;
 import com.android.exchange.Eas;
 import com.android.exchange.EasOutboxService;
 import com.android.exchange.EasSyncService;
+import com.android.exchange.SyncManager;
 import com.android.exchange.utility.CalendarUtilities;
 import com.android.exchange.utility.Duration;
 
@@ -35,14 +36,14 @@ import android.content.ContentResolver;
 import android.content.ContentUris;
 import android.content.ContentValues;
 import android.content.Entity;
+import android.content.Entity.NamedContentValues;
 import android.content.EntityIterator;
 import android.content.OperationApplicationException;
-import android.content.Entity.NamedContentValues;
 import android.database.Cursor;
+import android.database.DatabaseUtils;
 import android.net.Uri;
 import android.os.RemoteException;
 import android.provider.Calendar;
-import android.provider.SyncStateContract;
 import android.provider.Calendar.Attendees;
 import android.provider.Calendar.Calendars;
 import android.provider.Calendar.Events;
@@ -51,6 +52,7 @@ import android.provider.Calendar.ExtendedProperties;
 import android.provider.Calendar.Reminders;
 import android.provider.Calendar.SyncState;
 import android.provider.ContactsContract.RawContacts;
+import android.provider.SyncStateContract;
 import android.text.TextUtils;
 import android.util.Log;
 
@@ -59,10 +61,10 @@ import java.io.InputStream;
 import java.text.ParseException;
 import java.util.ArrayList;
 import java.util.GregorianCalendar;
+import java.util.Map.Entry;
 import java.util.StringTokenizer;
 import java.util.TimeZone;
 import java.util.UUID;
-import java.util.Map.Entry;
 
 /**
  * Sync adapter class for EAS calendars
@@ -282,9 +284,13 @@ public class CalendarSyncAdapter extends AbstractSyncAdapter {
         @Override
         public void wipe() {
             // Delete the calendar associated with this account
-            // TODO Make sure the Events, etc. are also deleted
-            mContentResolver.delete(Calendars.CONTENT_URI, CALENDAR_SELECTION,
-                    new String[] {mEmailAddress, Email.EXCHANGE_ACCOUNT_MANAGER_TYPE});
+            // CalendarProvider2 does NOT handle selection arguments in deletions
+            mContentResolver.delete(Calendars.CONTENT_URI, Calendars._SYNC_ACCOUNT +
+                    "=" + DatabaseUtils.sqlEscapeString(mEmailAddress) + " AND " +
+                    Calendars._SYNC_ACCOUNT_TYPE + "=" +
+                    DatabaseUtils.sqlEscapeString(Email.EXCHANGE_ACCOUNT_MANAGER_TYPE), null);
+            // Invalidate our calendar observers
+            SyncManager.unregisterCalendarObservers();
         }
 
         private void addOrganizerToAttendees(CalendarOperations ops, long eventId,