diff --git a/src/chunked_stream.js b/src/chunked_stream.js
index fe8388aa1..bef636147 100644
--- a/src/chunked_stream.js
+++ b/src/chunked_stream.js
@@ -363,7 +363,8 @@ var ChunkedStreamManager = (function ChunkedStreamManagerClosure() {
       var loadedRequests = [];
       for (var chunk = beginChunk; chunk < endChunk; ++chunk) {
 
-        var requestIds = this.requestsByChunk[chunk];
+        // The server might return more chunks than requested
+        var requestIds = this.requestsByChunk[chunk] || [];
         delete this.requestsByChunk[chunk];
 
         for (var i = 0; i < requestIds.length; ++i) {
diff --git a/src/network.js b/src/network.js
index 161833477..248cc8a0d 100644
--- a/src/network.js
+++ b/src/network.js
@@ -36,6 +36,10 @@
 //#endif
 
 var NetworkManager = (function NetworkManagerClosure() {
+
+  var OK_RESPONSE = 200;
+  var PARTIAL_CONTENT_RESPONSE = 206;
+
   function NetworkManager(url, args) {
     this.url = url;
     args = args || {};
@@ -156,7 +160,15 @@ var NetworkManager = (function NetworkManagerClosure() {
         return;
       }
 
-      if (xhr.status !== pendingRequest.expectedStatus) {
+      // From http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35.2:
+      // "A server MAY ignore the Range header". This means it's possible to
+      // get a 200 rather than a 206 response from a range request.
+      var ok_response_on_range_request =
+          xhr.status === OK_RESPONSE &&
+          pendingRequest.expectedStatus === PARTIAL_CONTENT_RESPONSE;
+
+      if (!ok_response_on_range_request &&
+          xhr.status !== pendingRequest.expectedStatus) {
         if (pendingRequest.onError) {
           pendingRequest.onError(xhr.status);
         }
@@ -166,18 +178,17 @@ var NetworkManager = (function NetworkManagerClosure() {
       this.loadedRequests[xhrId] = true;
 
       var chunk = getArrayBuffer(xhr);
-      if (pendingRequest.expectedStatus === 206) {
+      if (xhr.status === PARTIAL_CONTENT_RESPONSE) {
         var rangeHeader = xhr.getResponseHeader('Content-Range');
         var matches = /bytes (\d+)-(\d+)\/(\d+)/.exec(rangeHeader);
         var begin = parseInt(matches[1], 10);
-        var end = parseInt(matches[2], 10) + 1;
         pendingRequest.onDone({
           begin: begin,
-          end: end,
           chunk: chunk
         });
       } else {
         pendingRequest.onDone({
+          begin: 0,
           chunk: chunk
         });
       }