Here's a fix for Melbourne Cup Challenge that removes the disc protection and allows you to play from hard drive. This is for the PAL version. If anyone gets a chance to try it on the NTSC version (which I think is called Frankie Dettori Racing), let me know if it works.
# Game: Melbourne Cup Challenge (PAL)
# Title ID: 48450004
# Size: 1457MB (665 folders, 4834 files)
# Date: Jan 11, 2011
# Author: Lord Crass
# Disables DVD-check and allows play from hard drive
# Make a backup of the default.xbe file
# This patch assumes that you have copied the disc to the XBox hard drive with DVD2Xbox
# and that the long file names (64 characters) are truncated to 42 characters.
# Knock out call to cdrom0: check and set proper flags
# Redirect call to file rename code
# Add code to truncate file names on-the-fly in memory as they are used
# Set XBE header media type
# All game regions