Setting windowed res to 1440x838 results in pedia and other sub-windows not taking up the full area, seemingly limited to 1024x768 or something similar. Main overview window operates as you'd expect.
The research, production, and design screens not resizing for window resizes is a known issue / missing feature. If you want to work around it, restart the game after resizing to your desired window size.
Are you actually using v0.3.1-RC7? I'll assume not, but if so, update to v0.3.17 ASAP.
Mostly fixed in SVN.