Are you measuring the 360 distance? Just tested this game again now, and with your settings and a script to move exactly this distance the calculations are spot on.
It might be that either your WPS is set to a different value (perhaps 7, check the registry at HKEY_CURRENT_USER\Control Panel\Mouse\MouseSensitivity), or that your mouse driver loads a different profile with a different DPI when you launch the game. Or maybe something else that I've overlooked that affects the sensitivity in this game. Changing FOV does not change the 360 distance.