Can’t get image caching to work

Hi, I can't seem to get image caching to work. I'm using a InstallerChoices.xml file and InstaDMG 1.4b4 is creating a disk image in Caches/BaseImageCache folder called ".dmg" which means something's going wrong as looking at the script the cached disk image name should have the checksum of the disk image in it. How do I fix this so I don't have to wait for the script to reinstall the OS ever time I run it.