diff --git a/modules/binding-atom-abdera/src/main/java/org/apache/tuscany/sca/binding/atom/provider/AtomBindingInvoker.java b/modules/binding-atom-abdera/src/main/java/org/apache/tuscany/sca/binding/atom/provider/AtomBindingInvoker.java
index 92ccf2c..5982d77 100644
--- a/modules/binding-atom-abdera/src/main/java/org/apache/tuscany/sca/binding/atom/provider/AtomBindingInvoker.java
+++ b/modules/binding-atom-abdera/src/main/java/org/apache/tuscany/sca/binding/atom/provider/AtomBindingInvoker.java
@@ -96,7 +96,9 @@
 
             // Send an HTTP GET
             GetMethod getMethod = new GetMethod(uri + "/" + id);
-            getMethod.setRequestHeader("Authorization", authorizationHeader);
+            if (authorizationHeader != null) {
+                getMethod.setRequestHeader("Authorization", authorizationHeader);
+            }
             boolean parsing = false;
             try {
                 httpClient.executeMethod(getMethod);
@@ -173,7 +175,9 @@
 
             // Send an HTTP POST
             PostMethod postMethod = new PostMethod(uri);
-            postMethod.setRequestHeader("Authorization", authorizationHeader);
+            if (authorizationHeader != null) {
+                postMethod.setRequestHeader("Authorization", authorizationHeader);
+            }
             boolean parsing = false;
             try {
 
@@ -259,7 +263,9 @@
 
             // Send an HTTP PUT
             PutMethod putMethod = new PutMethod(uri + "/" + id);
-            putMethod.setRequestHeader("Authorization", authorizationHeader);
+            if (authorizationHeader != null) {
+                putMethod.setRequestHeader("Authorization", authorizationHeader);
+            }
 
             try {
 
@@ -310,7 +316,9 @@
 
             // Send an HTTP DELETE
             DeleteMethod deleteMethod = new DeleteMethod(uri + "/" + id);
-            deleteMethod.setRequestHeader("Authorization", authorizationHeader);
+            if (authorizationHeader != null) {
+                deleteMethod.setRequestHeader("Authorization", authorizationHeader);
+            }
             try {
                 httpClient.executeMethod(deleteMethod);
                 int status = deleteMethod.getStatusCode();
@@ -351,7 +359,9 @@
 
             // Send an HTTP GET
             GetMethod getMethod = new GetMethod(uri);
-            getMethod.setRequestHeader("Authorization", authorizationHeader);
+            if (authorizationHeader != null) {
+                getMethod.setRequestHeader("Authorization", authorizationHeader);
+            }
             boolean parsing = false;
             try {
                 httpClient.executeMethod(getMethod);
@@ -427,7 +437,9 @@
 
             // Send an HTTP GET
             GetMethod getMethod = new GetMethod(uri);
-            getMethod.setRequestHeader("Authorization", authorizationHeader);
+            if (authorizationHeader != null) {
+                getMethod.setRequestHeader("Authorization", authorizationHeader);
+            }
             getMethod.setQueryString(queryString);
             boolean parsing = false;
             try {
diff --git a/modules/binding-atom-abdera/src/main/java/org/apache/tuscany/sca/binding/atom/provider/AtomReferenceBindingProvider.java b/modules/binding-atom-abdera/src/main/java/org/apache/tuscany/sca/binding/atom/provider/AtomReferenceBindingProvider.java
index 65331af..1961146 100644
--- a/modules/binding-atom-abdera/src/main/java/org/apache/tuscany/sca/binding/atom/provider/AtomReferenceBindingProvider.java
+++ b/modules/binding-atom-abdera/src/main/java/org/apache/tuscany/sca/binding/atom/provider/AtomReferenceBindingProvider.java
@@ -49,7 +49,7 @@
 
     private RuntimeComponentReference reference;
     private AtomBinding binding;
-    private String authorizationHeader;
+    private String authorizationHeader = null;
     private HttpClient httpClient;
     private Mediator mediator;
     private DataType<?> itemClassType;
@@ -72,8 +72,10 @@
         this.mediator = mediator;
 
         // Prepare authorization header
-        String authorization = "admin" + ":" + "admin";
-        authorizationHeader = "Basic " + new String(Base64.encodeBase64(authorization.getBytes()));
+        // TUSCANY-3735: Don't send authorization header by default as this can cause problems.
+        // Commented out the following two lines until we have a better way to control this.
+        //String authorization = "admin" + ":" + "admin";
+        //authorizationHeader = "Basic " + new String(Base64.encodeBase64(authorization.getBytes()));
 
         // Create an HTTP client
         HttpConnectionManager connectionManager = new MultiThreadedHttpConnectionManager();
@@ -124,10 +126,12 @@
     public void start() {
 
         // Configure the HTTP client credentials
-        Credentials credentials = new UsernamePasswordCredentials("admin", "admin");
-        httpClient.getParams().setAuthenticationPreemptive(true);
-        URI uri = URI.create(binding.getURI());
-        httpClient.getState().setCredentials(new AuthScope(uri.getHost(), uri.getPort()), credentials);
+        // TUSCANY-3735: Don't use authentication by default as this can cause problems.
+        // Commented out the following four lines until we have a better way to control this.
+        //Credentials credentials = new UsernamePasswordCredentials("admin", "admin");
+        //httpClient.getParams().setAuthenticationPreemptive(true);
+        //URI uri = URI.create(binding.getURI());
+        //httpClient.getState().setCredentials(new AuthScope(uri.getHost(), uri.getPort()), credentials);
 
         // Find the get operation on the reference interface
         if (true) {