Windows Shell Context Menu

[95ulisse]

Hello everyone,
I'm new to the forum and this is only my second post, so I apologize in advance for any mistakes.

This is my situation:
I'm using Microsoft Visual Studio 2008 with .Net Framework 3.5.
I'm developing an extension of the Windows Shell Context menu, and I did it, but I have a problem:
when my menu is invoked on the links (*.lnk), it doesn't work and prevents the upper voices.
This only occurs on Vista and Seven, not on XP.
This is the IContextMenu.Qu eryContextMenu:

int IContextMenu.QueryContextMenu(uint hmenu,
              uint iMenu,
              int idCmdFirst,
              int idCmdLast,
              uint uFlags)
            {

                //Clicked file
                StringBuilder sb = new StringBuilder(1024);
                DllImports.DragQueryFile(m_hDrop, 0, sb, sb.Capacity + 1);

                //If it's a link (*.lnk) exits
                //Maybe the mistake is here, but I don't know!
                if (new FileInfo(sb.ToString()).Extension == ".lnk") { return 1; }

                // Adds the menus
                for (int i = 0; i < Menus.Length; i++)
                {

                    //Updates the ID
                    Menus[i].MenuItemInfo.wID += idCmdFirst;

                    //Verifies if the menu has some submenus
                    if (Menus[i].SubMenu != null) { PopolateSubMenu(Menus[i], idCmdFirst); }

                    //Adds the menu
                    DllImports.InsertMenuItem(hmenu, Menus[i].Position - 1, 1, ref Menus[i].MenuItemInfo);

                    //Adds the icon
                    if (Menus[i].Image != null) {
                        System.Drawing.Bitmap Bmp = Menus[i].Image;
                        DllImports.SetMenuItemBitmaps((IntPtr)hmenu, (IntPtr)(Menus[i].Position - 1), 0x400, Bmp.GetHbitmap(), Bmp.GetHbitmap());
                    }

                }

                // Returns the number of added menu item
                return (int)(NumeroMenu + 1);

            }

I don't know what to do!
Please help me!

Thank you in advance for your help!

PS: I apologize for my bad English, too: I'm Italian!