xml code:
<Window Id="WndSubclass" Version="1">
<Attributes>
<ShowInTaskbar>False</ShowInTaskbar>
</Attributes>
<Position Width="0" Height="0"/>
<TitleBar>
<AllowMinimize>False</AllowMinimize>
<AllowMaximize>False</AllowMaximize>
<AllowClose>False</AllowClose>
</TitleBar>
</Window>
That works perfectly. It seems that omitting the title bar element seems to cause it to be shown. Also, just setting Maximize to false (assuming Minimize and Close use their defaults of false) causes the title bar to be shown...
Anyway, thanks Cookie!