bootloader problems

[dooglex]

Hi, I'm trying to install ubuntu on my PC and dual boot with vista, i had ubuntu before but now cannot get it to boot.
I have vista on c: and ubuntu on another disk on a 30g partition, ubuntu installs fine when i reboot ubuntu has not touched the bootloader and it boots into vista, the install completes but i cannot boot the system!

[tuxxy]

Hit Delete usually at startup to enter the computer BIOS, make sure you have your Ubuntu drive selected as the first boot device.