--- a/mailnews/news/src/nsNNTPProtocol.cpp
+++ b/mailnews/news/src/nsNNTPProtocol.cpp
@@ -897,39 +897,52 @@ nsNNTPProtocol::OnCacheEntryAvailable(ns
 {
   nsresult rv = NS_OK;
 
   if (NS_SUCCEEDED(status))
   {
     nsCOMPtr<nsIMsgMailNewsUrl> mailnewsUrl = do_QueryInterface(m_runningURL, &rv);
     mailnewsUrl->SetMemCacheEntry(entry);
 
+    // If we have an empty cache entry with read access, we probably failed to
+    // clear it out from an error ealier. In this case, we'll simply try to
+    // write in the cache entry this time and hope we get luckier.
+    PRBool canRead = access & nsICache::ACCESS_READ;
+    if (canRead)
+    {
+      PRUint32 size;
+      entry->GetDataSize(&size);
+      if (size == 0)
+        canRead = PR_FALSE;
+    }
+
     // if we have write access then insert a "stream T" into the flow so data
     // gets written to both
-    if (access & nsICache::ACCESS_WRITE && !(access & nsICache::ACCESS_READ))
+    if (access & nsICache::ACCESS_WRITE && !canRead)
     {
       // use a stream listener Tee to force data into the cache and to our current channel listener...
       nsCOMPtr<nsIStreamListener> newListener;
       nsCOMPtr<nsIStreamListenerTee> tee = do_CreateInstance(NS_STREAMLISTENERTEE_CONTRACTID, &rv);
       NS_ENSURE_SUCCESS(rv, rv);
 
       nsCOMPtr<nsIOutputStream> out;
       rv = entry->OpenOutputStream(0, getter_AddRefs(out));
       NS_ENSURE_SUCCESS(rv, rv);
 
       rv = tee->Init(m_channelListener, out, nsnull);
       m_channelListener = do_QueryInterface(tee);
       NS_ENSURE_SUCCESS(rv, rv);
     }
-    else
+    else if (canRead)
     {
       rv = ReadFromMemCache(entry);
       if (access & nsICache::ACCESS_WRITE)
         entry->MarkValid();
-      if (NS_SUCCEEDED(rv)) return NS_OK; // kick out if reading from the cache succeeded...
+      if (NS_SUCCEEDED(rv))
+        return NS_OK; // kick out if reading from the cache succeeded...
     }
   } // if we got a valid entry back from the cache...
 
   // if reading from the cache failed or if we are writing into the cache, default to ReadFromImapConnection.
   return ReadFromNewsConnection();
 }
 
 nsresult nsNNTPProtocol::OpenCacheEntry()

new file mode 100644
--- /dev/null
+++ b/mailnews/news/test/unit/test_bug540288.js
@@ -0,0 +1,110 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* Tests that an empty cache entry doesn't return an empty message for news. */
+
+Components.utils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+// The basic daemon to use for testing nntpd.js implementations
+var daemon = setupNNTPDaemon();
+
+// Define these up here for checking with the transaction
+var type = null;
+var test = null;
+
+var server;
+var localserver;
+
+var streamListener =
+{
+  _data: "",
+
+  QueryInterface:
+    XPCOMUtils.generateQI([Ci.nsIStreamListener, Ci.nsIRequestObserver]),
+
+  // nsIRequestObserver
+  onStartRequest: function(aRequest, aContext) {
+  },
+  onStopRequest: function(aRequest, aContext, aStatusCode) {
+    do_check_eq(aStatusCode, 0);
+
+    // Reduce any \r\n to just \n so we can do a good comparison on any
+    // platform.
+    var reduced = this._data.replace(/\r\n/g, "\n");
+    do_check_eq(reduced, kSimpleNewsArticle);
+
+    // We must finish closing connections and tidying up after a timeout
+    // so that the thread has time to unwrap itself.
+    do_timeout(0, doTestFinished);
+  },
+
+  // nsIStreamListener
+  onDataAvailable: function(aRequest, aContext, aInputStream, aOffset, aCount) {
+    let scriptStream = Cc["@mozilla.org/scriptableinputstream;1"]
+                         .createInstance(Ci.nsIScriptableInputStream);
+
+    scriptStream.init(aInputStream);
+
+    this._data += scriptStream.read(aCount);
+  }
+};
+
+function doTestFinished() {
+    localserver.closeCachedConnections();
+
+    server.stop();
+
+    var thread = gThreadManager.currentThread;
+    while (thread.hasPendingEvents())
+      thread.processNextEvent(true);
+
+    do_test_finished();
+}
+
+const kCacheKey = "news://localhost:" + NNTP_PORT + "/TSS1%40nntp.test";
+
+function run_test() {
+  type = "RFC 977";
+  var handler = new NNTP_RFC977_handler(daemon);
+  localserver = setupLocalServer(NNTP_PORT);
+  server = new nsMailServer(handler);
+  server.start(NNTP_PORT);
+
+  try {
+    // Add an empty message to the cache
+    var cache = Cc["@mozilla.org/messenger/nntpservice;1"]
+                  .getService(Ci.nsINntpService)
+                  .cacheSession;
+    var cacheEntry = cache.openCacheEntry(kCacheKey, Ci.nsICache.ACCESS_WRITE,
+                                          true);
+    cacheEntry.markValid();
+    var firstAccess = cacheEntry.fetchCount;
+    cacheEntry.close();
+
+    // Get the folder and new mail
+    var folder = localserver.rootFolder.getChildNamed("test.subscribe.simple");
+    folder.clearFlag(Ci.nsMsgFolderFlags.Offline);
+    folder.getNewMessages(null, {
+      OnStopRunningUrl: function () { localserver.closeCachedConnections(); }});
+    server.performTest();
+
+    do_check_eq(folder.getTotalMessages(false), 1);
+    do_check_true(folder.hasNewMessages);
+
+    server.resetTest();
+
+    var message = folder.firstNewMessage;
+
+    var messageUri = folder.getUriForMsg(message);
+
+    var nntpService = Cc["@mozilla.org/messenger/nntpservice;1"]
+      .getService(Ci.nsIMsgMessageService);
+
+    do_test_pending();
+
+    nntpService.DisplayMessage(messageUri, streamListener, null, null, null, {});
+    // Get the server to run
+    server.performTest();
+  } catch (e) {
+    server.stop();
+    do_throw(e);
+  }
+};