Why are my custom context menu commands disabled when I right click first?

We have a SyntaxEditor that uses a custom context menu, like so:

<Window 
    x:Class="ContextMenuProblem.MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" 
    xmlns:apeditor="clr-namespace:ActiproSoftware.Windows.Controls.SyntaxEditor;assembly=ActiproSoftware.SyntaxEditor.Wpf" 
    Title="MainWindow" 
    Height="350"
    Width="525"
    >
    <Grid>
        <apeditor:SyntaxEditor
            IsDefaultContextMenuEnabled="False"
            >
            <apeditor:SyntaxEditor.ContextMenu>
                <ContextMenu>
                    <MenuItem
                        Header="Cut"
                        Command="apeditor:EditorCommands.CutToClipboard"
                        InputGestureText="Ctrl+X"
                        />
                    <MenuItem
                        Header="Copy"
                        Command="apeditor:EditorCommands.CopyToClipboard"
                        InputGestureText="Ctrl+C"
                        />
                    <MenuItem
                        Header="Paste"
                        Command="apeditor:EditorCommands.PasteFromClipboard"
                        InputGestureText="Ctrl+V"
                        />
                    <MenuItem
                        Header="Delete"
                        Command="apeditor:EditorCommands.Delete"
                        />
                    <Separator
                        />
                    <MenuItem
                        Header="Select All"
                        Command="apeditor:EditorCommands.SelectAll"
                        InputGestureText="Ctrl+A"
                        />
                </ContextMenu>
            </apeditor:SyntaxEditor.ContextMenu>
        </apeditor:SyntaxEditor>
    </Grid>
</Window>

This works fine for us, except for one problem. When running this, if a user right clicks in the syntax editor (before left clicking - meaning no insertion pointer is present), all the commands are disabled. However ,when I use the built-in context menu and right click first, nearly all commands are enabled. 

What can I do to ensure that commands are enabled on the first right click? While I realize overriding CreateDefaultContextMenu is the recommended approach, we prefer to not extend controls whenever possible. I figure I could probably create a behavior that performs a left click on a right click but that seems hacky. I was wondering if there's a better alternative or a workaround.

Thanks,

-Craig