As of the latest Beta (0.90), I can't change my resolution any more.
My setup:
Primary monitor with 1680x1050
Secondary monitor with 1280x1024
Last version ran, as usual, on my primary monitor with full resolution. The current version also runs on my primary monitor, but for some reason always defaults back to a maximum resolution of 1280x1024, which is suspiciously the same as my secondary monitor. I tried running it with fullscreen off, which also ignores the resolution I set (1680) and runs in a 1280 window.