Description of problem:
When trying to do an install via "Network install tree" I get a backtrace about 

Version-Release number of selected component (if applicable):
virt-manager-0.6.1-1.fc10

How reproducible:
every time

Steps to Reproduce:
1. try to do a network install of rawhide:

2.
3.
  
Actual results:
Unable to complete install '<type 'exceptions.OSError'> [Errno 13] Permission denied: '/var/lib/libvirt/boot/virtinst-.treeinfo.XIYNd_'
Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/create.py", line 717, in do_install
    dom = guest.start_install(False, meter = meter)
  File "/usr/lib/python2.5/site-packages/virtinst/Guest.py", line 730, in start_install
    self._prepare_install(meter)
  File "/usr/lib/python2.5/site-packages/virtinst/FullVirtGuest.py", line 315, in _prepare_install
    distro = self.os_distro)
  File "/usr/lib/python2.5/site-packages/virtinst/DistroManager.py", line 269, in prepare
    self._prepare_kernel_and_initrd(guest, distro, meter)
  File "/usr/lib/python2.5/site-packages/virtinst/DistroManager.py", line 235, in _prepare_kernel_and_initrd
    arch=arch)
  File "/usr/lib/python2.5/site-packages/virtinst/DistroManager.py", line 109, in acquireKernel
    scratchdir=scratchdir, arch=arch)
  File "/usr/lib/python2.5/site-packages/virtinst/DistroManager.py", line 90, in _storeForDistro
    if store.isValidStore(fetcher, progresscb):
  File "/usr/lib/python2.5/site-packages/virtinst/OSDistro.py", line 200, in isValidStore
    if self._hasTreeinfo(fetcher, progresscb):
  File "/usr/lib/python2.5/site-packages/virtinst/OSDistro.py", line 66, in _hasTreeinfo
    tmptreeinfo = fetcher.acquireFile(".treeinfo", progresscb)
  File "/usr/lib/python2.5/site-packages/virtinst/ImageFetcher.py", line 98, in acquireFile
    tmpname = self.saveTemp(file, prefix=base + ".")
  File "/usr/lib/python2.5/site-packages/virtinst/ImageFetcher.py", line 43, in saveTemp
    (fd, fn) = tempfile.mkstemp(prefix="virtinst-" + prefix, dir=self.scratchdir)
  File "/usr/lib64/python2.5/tempfile.py", line 302, in mkstemp
    return _mkstemp_inner(dir, prefix, suffix, flags)
  File "/usr/lib64/python2.5/tempfile.py", line 236, in _mkstemp_inner
    fd = _os.open(file, flags, 0600)
OSError: [Errno 13] Permission denied: '/var/lib/libvirt/boot/virtinst-.treeinfo.XIYNd_'
'

Expected results:
no backtrace

Additional info:
This has been happening for a while now...
I am not sure about in rawhide, and don't have a bare metal rawhide box with vt right now.