A test that has a Select step to select an option from a drop down intermittently yields:

ExecuteCommand failed!
InError set by the client. Client Error:
System.InvalidCastException: Unable to cast COM object of type 'mshtml.HTMLDocumentClass' to interface type 'mshtml.IHTMLDocument4'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{3050F69A-98B5-11CF-BB82-00AA00BDCE0B}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).
   at System.StubHelpers.StubHelpers.GetCOMIPFromRCW(Object objSrc, IntPtr pCPCMD, IntPtr& ppTarget, Boolean& pfNeedsRelease)
   at mshtml.HTMLDocumentClass.IHTMLDocument4_CreateEventObject(Object& pvarEventObject)
   at ArtOfTest.InternetExplorer.IECommandProcessor.InvokeEvent(IHTMLElement target, String data)
   at ArtOfTest.InternetExplorer.IECommandProcessor.ProcessActionCommands(BrowserCommand request)
   at ArtOfTest.InternetExplorer.IECommandProcessor.ProcessCommandInternal(WebBrowserClass ieInstance, BrowserCommand request, IHTMLDocument2 document)
BrowserCommand (Type:'Action',Info:'NotSet',Action:'InvokeEvent',Target:'ElementId (tagName: 'select',occurrenceIndex: '0')',Data:'onchange--@@--null',ClientId:'Client_53fdecf7-3d31-425f-86d1-01aa19d1cf1f',HasFrames:'False',FramesInfo:'',TargetFrameIndex:'-1',InError:'True',Response:'System.InvalidCastException: Unable to cast COM object of type 'mshtml.HTMLDocumentClass' to interface type 'mshtml.IHTMLDocument4'. This operation failed because the QueryInterface call on the COM component for the interface with IID '{3050F69A-98B5-11CF-BB82-00AA00BDCE0B}' failed due to the following error: No such interface supported (Exception from HRESULT: 0x80004002 (E_NOINTERFACE)).
   at System.StubHelpers.StubHelpers.GetCOMIPFromRCW(Object objSrc, IntPtr pCPCMD, IntPtr& ppTarget, Boolean& pfNeedsRelease)
   at mshtml.HTMLDocumentClass.IHTMLDocument4_CreateEventObject(Object& pvarEventObject)
   at ArtOfTest.InternetExplorer.IECommandProcessor.InvokeEvent(IHTMLElement target, String data)
   at ArtOfTest.InternetExplorer.IECommandProcessor.ProcessActionCommands(BrowserCommand request)
   at ArtOfTest.InternetExplorer.IECommandProcessor.ProcessCommandInternal(WebBrowserClass ieInstance, BrowserCommand request, IHTMLDocument2 document)')
InnerException: none.

It happens 100% of the time in the customers environment. I can repro it about 25% of the time on my machine.

Repro steps will be given on the internal bug report.