You'll need to install the whole python-virtinst package. Virt-manager calls modules in the underlying python-virtinst package that have had significant changes in the last month.
i picked up virtinst from there there are no install instructions in README http://virt-manager.et.redhat.com/download/sources/virtinst/virtinst-0.100.0.tar.gz how to i install the whole package. Satya ps: do you guys hang around on freenode
