You saw my code to show the current window right? User32_ShowWindow(TheWindow,1)
Ah! It's clicked now... I didn't realise the Windows API did not show 'em by default so it was confusing me a bit as I was initialising ModPlug with hidden|false. If I ShowWindow the ChildWindow then up it pops as it should - always the silly little things that get you!
Shame about the SDK :(