I am in a similar situation. What I did was changed the Grub loader to be on Vista by default and set it to a 3 second countdown so it was pretty much automatic anyway.
Use this command.
sudo gedit /boot/grub/menu.lst
You are now in the grub options file and you can edit it as you are admin (sudo). Change the setting timeout from 10 to whatever you want. Change default from 0 to presumably 4 (the first entry is 0, Vista is usally the 5th entry so 4).