Description of problem:
It always fails when using -b and a valid; just created livecd as it.

Version-Release number of selected component (if applicable):
14.2-1

How reproducible:
Create a livecd using the following kickstart: /usr/share/spin-kickstarts/fedora-live-base.ks

Steps to Reproduce:
1. Create a live cd: livecd-creator -c /usr/share/spin-kickstarts/fedora-live-base.ks -f some_cool_label --releasever=1 -v --logfile=livecd-creator.log
2. After successfully finishing it, create another one, with a slight change (add a package to the ks file) and use the one just created as base: livecd-creator -c fedora-live-base-modified.ks -f some_cooler_label --releasever=2 -v --logfile=livecd-creator.log -b some_cool_label.iso
  
Actual results:
It fails horribly:

...

Traceback (most recent call last):
  File "/usr/bin/livecd-creator", line 150, in <module>
    sys.exit(main())
  File "/usr/bin/livecd-creator", line 134, in main
    creator.configure()
  File "/usr/lib/python2.7/site-packages/imgcreate/creator.py", line 742, in configure
    self._create_bootconfig()
  File "/usr/lib/python2.7/site-packages/imgcreate/live.py", line 204, in _create_bootconfig
    self._configure_bootloader(self.__ensure_isodir())
  File "/usr/lib/python2.7/site-packages/imgcreate/live.py", line 683, in _configure_bootloader
    self._configure_syslinux_bootloader(isodir)
  File "/usr/lib/python2.7/site-packages/imgcreate/live.py", line 583, in _configure_syslinux_bootloader
    cfg += self.__get_image_stanzas(isodir)
  File "/usr/lib/python2.7/site-packages/imgcreate/live.py", line 482, in __get_image_stanzas
    (is_xen, isDracut) = self.__copy_kernel_and_initramfs(isodir, version, index)
  File "/usr/lib/python2.7/site-packages/imgcreate/live.py", line 404, in __copy_kernel_and_initramfs
    isodir + "/isolinux/initrd" + index + ".img")
  File "/usr/lib64/python2.7/shutil.py", line 81, in copyfile
    with open(src, 'rb') as fsrc:
IOError: [Errno 2] No such file or directory: '/var/tmp/imgcreate-w7cYZ3/install_root/boot/initrd-2.6.35.13-91.fc14.x86_64.img'


Expected results:
It should build the new livecd in half the time (since it will download and install what's missing only)

Additional info:

I'm trying this on a minimal installation; with kickstart files installed and liveusb-creator installed.

Also, on non-minimal (desktops), gvfs gets in the way a lot! It claims the /dev/loopX device and it becomes impossible to unmount...