I have created a context menu when a user right clicks on a link. I've
implemented IDocHostUIHandler and post the menu if the right click
happened on a link:

public uint ShowContextMenu(uint dwID, ref tagPOINT ppt, object
pcmdtReserved, object pdispReserved)
{
    Write(string.Format("Context menu on: {0}",
pdispReserved.GetType().ToString()));

    if (pdispReserved is HTMLAnchorElementClass)
    {
         // create the menu
         .....
         return 0;
    }
    return 1
}

On some PC's the first time the user right clicks a link, the above
method is calles, but the menu is NOT posted because the type of the
pDispReserved object appears to be "System.__ComObject" instead of
"HTMLAnchorElementClass".

Why is the pdispReserved object sometimes "System.__ComObject". Can
anyone explain what "System.__ComObject" is?

Thanks

Mitch