ok, so grub 2 has officially pissed me off. There is a way to make it load windows by default, not using the number of the menu entry (which changes every time you update the damned kernel). Instead you can use the exact string of the title of the menu entry. wonderful. but how does one find this easily?
os-prober returns: /dev/sda1:Windows 7 (loader):Windows:Chain
update-grub returns: Found Windows 7 (loader) on /dev/sda1
neither of these work. if you type: grep Windows /boot/grub/grub.cfg you will see the string you need, which in my case was: Windows 7 (loader) (on /dev/sda1) therefore in /etc/default/grub should be GRUB_DEFAULT= "Windows 7 (loader) (on /dev/sda1)"