Description of problem:
Open virt-manager and set it to boot from an .iso in your home directory.
The file is now owned by user libvirt-qemu and group kvm.
Version-Release number of selected component (if applicable):
virt-manager 0.9.5-1ubuntu1 on Ubuntu 13.10 "Saucy" Alpha
A friend reproduced the bug with 0.9.1-1ubuntu5 on Ubuntu 12.04 LTS
virt-manager should not need to take ownership of a read-only .iso just to read it.
*** This bug has been marked as a duplicate of bug 885410 ***