Thanks for the report! I managed to fix this, and a new version is available for download.
There is some functionality that resets the window to 1024x768 if it's ever resized below those dimensions. On tight monitors (such as a 1366x768 laptop, minus some space for the taskbar) it can get caught in a reset loop. Any sized window is now allowed. At smaller sizes, some UI elements might go out of window bounds but everything should fit as long as it isn't significantly smaller than that minimum.