1) Open any web test
2) Enable annotation
3) Try to run test in FF

Expected: The test to run
Actual:
1) FF opens
2) You see Preparing for automation in FF
3) The Visual Debugger opens and you see Navigating to XXXX in the Visual Debugger
4) Nothing more happens, even if you wait 5 minutes. The test does not fail, does not time out or abort. You can Abort it.

In the log is this:

[05/07 19:27:37,ArtOfTest.Runner.exe(21016:9),UIAutomation] AutomationExtensions.AddStructureChangedEventHandler() : Added a structure change handler on element System.Windows.Automation.AutomationElement scope Subtree.
[05/07 19:27:37,ArtOfTest.Runner.exe(21016:5),TestStudio] VisualDebugger.CheckPause() : VisualDebugger::CheckPause::Start
[05/07 19:27:37,ArtOfTest.Runner.exe(21016:5),TestStudio] VisualDebugger.CheckPause() : VisualDebugger::CheckPause::End
[05/07 19:27:44,ArtOfTest.Runner.exe(21016:22)] First trace message from foreground thread "AnnotatorUIThread" (managed ID = 22, native ID = 19712).
[05/07 19:27:44,ArtOfTest.Runner.exe(21016:22),Error] <>c__DisplayClass11.<CreateHwndSource>b__10() : EXCEPTION! (see below)
     Outer Exception Type: System.TimeoutException
     Message: Wait for condition has timed out
     HRESULT: 0x80131505 (Official ID (if app.) = COR_E_TIMEOUT, Error Bit = FAILED, Facility = FACILITY_URT, Code = 5381)
     Call Stack:
          at ArtOfTest.Common.WaitSync.CheckResult(WaitSync wait, String extraExceptionInfo, Object target)
          at ArtOfTest.Common.WaitSync.For[T](Predicate`1 predicate, T target, Boolean invertCondition, Int32 timeout, WaitResultType errorResultType)
          at ArtOfTest.Common.WaitSync.For[T](Predicate`1 predicate, T target, Boolean invertCondition, Int32 timeout)
          at ArtOfTest.WebAii.BrowserSpecialized.Firefox.FireFoxActions.GetContentRectangle()
          at ArtOfTest.WebAii.Core.Browser.get_ContentRectangle()
          at ArtOfTest.WebAii.Win32.Annotator.<>c__DisplayClass4.<AnnotateInternal>b__2()
          at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
          at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
          at System.Windows.Threading.DispatcherOperation.InvokeImpl()
          at System.Windows.Threading.DispatcherOperation.InvokeInSecurityContext(Object state)
          at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
          at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx)
          at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
          at System.Windows.Threading.DispatcherOperation.Invoke()
          at System.Windows.Threading.Dispatcher.ProcessQueue()
          at System.Windows.Threading.Dispatcher.WndProcHook(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
          at MS.Win32.HwndWrapper.WndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam, Boolean& handled)
          at MS.Win32.HwndSubclass.DispatcherCallbackOperation(Object o)
          at System.Windows.Threading.ExceptionWrapper.InternalRealCall(Delegate callback, Object args, Int32 numArgs)
          at MS.Internal.Threading.ExceptionFilterHelper.TryCatchWhen(Object source, Delegate method, Object args, Int32 numArgs, Delegate catchHandler)
          at System.Windows.Threading.Dispatcher.LegacyInvokeImpl(DispatcherPriority priority, TimeSpan timeout, Delegate method, Object args, Int32 numArgs)
          at MS.Win32.HwndSubclass.SubclassWndProc(IntPtr hwnd, Int32 msg, IntPtr wParam, IntPtr lParam)
          at MS.Win32.UnsafeNativeMethods.DispatchMessage(MSG& msg)
          at System.Windows.Threading.Dispatcher.PushFrameImpl(DispatcherFrame frame)
          at System.Windows.Threading.Dispatcher.PushFrame(DispatcherFrame frame)
          at ArtOfTest.Common.Win32.AdornerWindow.<>c__DisplayClass11.<CreateHwndSource>b__10()