Install DirectX Debug Runtime !!!
You can't create D3DPOOL_MANAGED rendertarget only D3DPOOL_DEFAULT.

This one works:
[pascal] // Create the blank texture
Result:= pd3dDevice.CreateTexture(1, 1, 1,
D3DUSAGE_RENDERTARGET,
D3DFMT_A16B16G16R16F,
D3DPOOL_DEFAULT,
g_pTexScratch, nil);
if V_Failed(Result) then Exit;[/pascal]