ciao !
after reading a thread i gave a more carefull look at my vista/linux dual boot..
i'm still keeping grub on mbr as my defauly bldr..installed from vista easy bcd AND vistabootpro to give them a look..they can't load linux by themselves,i'm still keeping grub on mbr as my defauly bldr..but they during boot let you eventually choose to access IN A SECOND the repair options by pressing only one time F8 instead of start hitting many,many times F8 in case of need just as you turn on pc until you can access these options ..
SO MY SUGGESTION IS TO KEEP GRUB AS DEFAULT BOOT LOADER ON MBR AND THEN INSTALL EASY BCD-it's much better than vistabootpro which is thought essentially to let you boot between xp and vista- AND USE BCD WITHOUT OVERWRITING GRUB ! ONLY FOR HAVING A FASTER AND EASIER ACCESS TO VISTA BOOT AND REPAIR OPTIONS..
You can look at the post for vista/linux dual boot for a more complete understanding
SEE YA !