Windows 7 Bootloader installs to wrong drive when installing from secondary hard drive

I have set up an unattended installation of Windows 7, but my setup causes the bootloader to be installed to the wrong drive. Here is the setup:

Drive 0 (OS Drive): This is the drive that the OS gets installed to. This is also the drive I want the bootloader on. All Windows files are installed to this drive, but bootloader is not.

Drive 1 (Installer Drive): This drive contains all the files from the windows 7 dvd, with the sources/install.wim file replaced with my custom version. This is the drive that the system boots to when I go to install windows, and is attached temporarily. This is the drive the bootloader actually gets installed to.

Since the whole idea here is to allow for unattended imaging of the OS, booting temporarily using the installer drive and “repairing” the installation post-install is not an option.

I realize that I could circumvent this problem by deploying the OS over the network using the MDT, but that scenario is less than ideal in some situations, so I need both working.

I need a way to tell the installer to install the bootloader to the hard drive the operating system is being installed to, ignoring the other hard drives attached to the system.

Some google-searched pages which detailing similar problems:

http://www.sevenforums.com/installation-setup/37210-windows-7-boot-manager-wrong-drive.html

http://social.technet.microsoft.com/Forums/en-US/w7itproinstall/thread/7eb4e0af-21f2-472f-89ba-a879cece5ef3/