Grub problems on dual boot

view story

http://askubuntu.com – I did this very clever decision to set windows 7 bootloader to ubuntu. and now i cannot boot back to windows if i try to boot via grub it flashes the windows bootloader for half a second and goes back to Grub, also the safemode of windows ceased to function, so i cannot go back and change the settings. i am totally screwed here and would not want to install the OS (both of them) again.... (HowTos)