That file is created during the livefs build and should most certainly be in the squashfs. If you mount the squashfs file from the CD image itself (mount -t squashfs /cdrom/casper/filesystem.squashfs /mnt), can you see the modules.dep file in the mountpoint?
That file is created during the livefs build and should most certainly be in the squashfs. If you mount the squashfs file from the CD image itself (mount -t squashfs /cdrom/ casper/ filesystem. squashfs /mnt), can you see the modules.dep file in the mountpoint?