Operating system and graphics card
Windows 7 64 Bit
Broken: (example: 2.69.7 4b206af, see splash screen)
Short description of error
Specific Editor window changes its ratio by dragging Blender small and big. Means, Blender is maximized, you turn it windowed and drag it small. And when you maximize Blender again, then the formerly closed editor window is now wide open. See screenshots.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps
I stumbled across this behavior when i wanted to place the Timeline below the Info editor at the top. And started to wonder why i now every now and then had to pull the Timeline editor up so that it is closed again.
Add another Editor type below the Info toolbar. Drag it up so that it shows closed and just the header is visible. Now drag Blender smaller. Then drag it bigger again. You will notice that the editor window where just the header should be visible now opens more and more up. Other areas keeps their ratio though.