--- a/security/manager/ssl/tests/unit/test_ocsp_timeout.js
+++ b/security/manager/ssl/tests/unit/test_ocsp_timeout.js
@@ -19,20 +19,16 @@ let gSocketListener = {
   onSocketAccepted: function(serverSocket, socketTransport) {
     socketTransport.setTimeout(Ci.nsISocketTransport.TIMEOUT_CONNECT, 30);
     socketTransport.setTimeout(Ci.nsISocketTransport.TIMEOUT_READ_WRITE, 30);
   },
 
   onStopListening: function(serverSocket, socketTransport) {}
 };
 
-const ua = Cc["@mozilla.org/network/protocol;1?name=http"]
-             .getService(Ci.nsIHttpProtocolHandler).userAgent;
-const gIsWinXP = ua.indexOf("Windows NT 5.1") != -1;
-
 function run_test() {
   do_get_profile();
 
   add_tls_server_setup("OCSPStaplingServer");
 
   let socket = Cc["@mozilla.org/network/server-socket;1"]
                  .createInstance(Ci.nsIServerSocket);
   socket.init(8080, true, -1);
@@ -55,22 +51,20 @@ function add_tests_in_mode(useHardFail) 
 
   add_connection_test("ocsp-stapling-none.example.com", useHardFail
                       ? getXPCOMStatusFromNSS(SEC_ERROR_OCSP_SERVER_ERROR)
                       : Cr.NS_OK, clearSessionCache);
 
   // Reset state
   add_test(function() {
     let endTime = new Date();
-    // With OCSP hard-fail on, we timeout after 10 seconds (except if the
-    // OS is Windows XP, which occasionally times out too quickly for reasons
-    // unknown).
+    // With OCSP hard-fail on, we timeout after 10 seconds.
     // With OCSP soft-fail, we timeout after 2 seconds.
     if (useHardFail) {
-      do_check_true((endTime - startTime) > 10000 || gIsWinXP);
+      do_check_true((endTime - startTime) > 10000);
     } else {
       do_check_true((endTime - startTime) > 2000);
     }
     // Make sure we didn't wait too long.
     // (Unfortunately, we probably can't have a tight upper bound on
     // how long is too long for this test, because we might be running
     // on slow hardware.)
     do_check_true((endTime - startTime) < 60000);

--- a/security/manager/ssl/tests/unit/xpcshell.ini
+++ b/security/manager/ssl/tests/unit/xpcshell.ini
@@ -47,17 +47,18 @@ run-sequentially = hardcoded ports
 skip-if = os == "android"
 [test_ocsp_required.js]
 run-sequentially = hardcoded ports
 # Bug 1009158: this test times out on Android
 skip-if = os == "android"
 [test_ocsp_timeout.js]
 run-sequentially = hardcoded ports
 # Bug 1009158: this test times out on Android
-skip-if = os == "android"
+# Bug 1005266: intermittent failures on Windows
+skip-if = os == "android" || os == "win"
 [test_cert_signatures.js]
 [test_ev_certs.js]
 run-sequentially = hardcoded ports
 # Bug 1009158: this test times out on Android
 # Bug 1008316: Test needs modification to work on B2G
 fail-if = os == "android" || buildapp == "b2g"
 [test_getchain.js]
 [test_cert_overrides.js]