Ok - this is exactly as expected.

Your attempt to open a 1024x768 window resulted - because of the title bar - in a wrong sized window under 6.50.2:

D3D_Init Window: 1024x768x32 -> Window: 1x1024x753x32

And to failure under 6.50.6:

D3D_Init Window: 1024x768x32 -> 1024x753 failed

So, 6.50.6 behaves correct. It was the old version, 6.50.2 that behaved incorrect.