Excel 2010 ribbon command Paste not activated by Ctrl-V

private const int WM_USER = 0x0400;
private const int WM_CtrlV_PRESSED_IN_EXCEL = WM_USER + 1112;
private const int WM_CtrlV_PRESSED_IN_FORMULABAR = WM_USER + 1113;
private const int WM_CtrlV_PRESSED_IN_CELLEDITOR = WM_USER + 1114;

private void AddinModule_OnKeyDown(object sender, ADXKeyDownEventArgs e) {

    // you must not use the Excel object model in this method
    // use AddinModule_OnSendMessage instead; see below

    if (e.Ctrl && !e.Shift && e.VirtualKey == ( int )Keys.V) {
        IntPtr focusedWindow = NativeMethods.GetFocus();
        string focusedWindowClassName = NativeMethods.GetClassName(focusedWindow);
        bool doesAddinHandleThis = false;
        System.Diagnostics.Debug.WriteLine("!!! focusedWindowClassName=" + focusedWindowClassName);
        if (focusedWindowClassName == "EXCEL7") {
            // Excel itself
            doesAddinHandleThis = true;
            this.SendMessage(WM_CtrlV_PRESSED_IN_EXCEL);
        } else if (focusedWindowClassName == "EXCEL<") {
            // Formula bar window
            //doesAddinHandleThis = true;
            //this.SendMessage(WM_CtrlV_PRESSED_IN_FORMULABAR);
        } else if (focusedWindowClassName == "EXCEL6") {
            // in-place cell editor window
            //doesAddinHandleThis = true;
            //this.SendMessage(WM_CtrlV_PRESSED_IN_CELLEDITOR);
        } else if (focusedWindowClassName == "EXCEL=") {
            // sheet name editor window
        }
        e.Handled = doesAddinHandleThis;
    }
}

private void AddinModule_OnSendMessage(object sender, ADXSendMessageEventArgs e) {
    if (e.Message == WM_CtrlV_PRESSED_IN_EXCEL) {
        // you can use the Excel object model here
    }
}
...
using System;
using System.Text;
using System.Runtime.InteropServices;
...
class NativeMethods {
    [DllImport("user32.dll")]
    public static extern IntPtr GetFocus();

    [DllImport("user32.dll")]
    public static extern int GetClassName(IntPtr hWnd, StringBuilder buf, int nMaxCount);

    public static string GetClassName(IntPtr hWnd) {
        string result = String.Empty;
        int MaxCharsCount = 256;
        StringBuilder className = new StringBuilder(MaxCharsCount);
        if (GetClassName(hWnd, className, MaxCharsCount) > 0) {
            result = className.ToString();
        }
        return result;
    }
}

//Excel 2010: handling Ctrl-V paste
if (HostType == ADXOfficeHostApp.ohaExcel && HostMajorVersion <= 14)
{
  this.OnKeyDown += ReportMakerAddIn_OnKeyDown;
}

        /// <summary>
        /// Handle OnKeyDown event
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void ReportMakerAddIn_OnKeyDown(object sender, ADXKeyDownEventArgs e)
        {
            // you must not use the Excel object model in this method 
            // use AddinModule_OnSendMessage instead; see below 

            bool doesAddinHandleThis = false;
            if (e.Ctrl && !e.Shift && e.VirtualKey == (int)Keys.V)
            {
                IntPtr focusedWindow = Win32Natives.GetFocus();
                string focusedWindowClassName = Win32Natives.GetClassName(focusedWindow);
                System.Diagnostics.Debug.WriteLine("!!! focusedWindowClassName=" + focusedWindowClassName);
                if (focusedWindowClassName == "EXCEL7")
                {
                    // Excel itself 
                    //doesAddinHandleThis = true;
                    //this.SendMessage(WM_CtrlV_PRESSED_IN_EXCEL);

                    doesAddinHandleThis = true;
                    bool mustCancel = true; // Not used
                    XLRibbon.XLHandlePaste(out mustCancel, PasteSelfIfNotCancelled: true);
                }
                else if (focusedWindowClassName == "EXCEL<")
                { ... the other windows ...

        /// <summary>
        /// Handle the Paste
        /// </summary>
        /// <param name="DoCancel"></param>
        /// <param name="PasteSelfIfNotCancelled"></param>
        public void XLHandlePaste(out bool DoCancel, bool PasteSelfIfNotCancelled= false)
        {
            string thePastedDescriptor = "";
            string Message = "";
            DoCancel = false;
            try
            {
                // If this fails, Excel is busy so cancel it
                appExcel.StatusBar = " "; // Clear
                // Check for marker text in clipboard content
                if (Globals.ClipBoardOffice.GetClipboardText(out thePastedDescriptor, ""Application": "SP_SaaS""))
                {
                    // Already marked?
                    if (WordExcelUtils.AskDocMarkedRMReport(this.workbook, out DoCancel))
                    {
                        // Do insert, continue
                        DoCancel = true; // always true
                    }
                    else
                    {
                        if (PasteSelfIfNotCancelled && !DoCancel)
                        {
                            // Paste clipboard content as it is
                            this.worksheet.Paste();
                        }
                        // Stop
                        return;
                    }

                    // ... Construction of insertion string and the insertion itself ...