On the Windows platform, the interior of the 4D application window became two pixels smaller on all four sides in v6.5 than it was in v6. In v6, the inside of the 4D application window was missing the three-dimensional bevel typical in the Windows interface. This was added in 4D V6.5, which subracted two pixels on each of the four sides from the space available to display your own windows. This meant that your largest window needed to be four pixels narrower and four pixels shorter than before.
In 4D v6.5.3, this bevel on the inside of the 4D application window has been removed, so the amount of space available in which you can open your largest possible window is now the same as it was in v6.
For viewing on a 640 by 480 pixel screen display using the standard settings in the Windows Display control panel, the largest size that a type 8 window can be fully displayed in v6.5.3 is 624 pixels wide by 379 pixels high. On an 800 x 600 monitor, your largest type 8 window should be 784 x 499 pixels.