install fails from NFS distribution w/ISO files (anaconda problem?)

I'm trying to Kickstart Fedora14 & 15, using NFS for the distribution
with ISO file(s) in the NFS directory -- same method used successfully
for prior Fedora, Centos5,6 etc.  E.g. from a ks.cfg file:

   nfs --server kick.foo.com --dir /dist/fedora/x86_64/14/

and the /dist/fedora/x86_64/14/ directory contains the Fedora14 DVD ISO
(plus the images/ subdir also, fwiw).

Same NFS server, client hardware, Kickstart server, network, etc. used
successfully with earlier Fedora, and Centos5 & 6, etc.

But with Fedora14 & 15, I get an error popup on console:

        The following error occurred while setting
        up the installation repository:
        
        (16, 'umount.nfs: /mnt/source: device is
        busy\numount.nfs: /mnt/source: device is
        busy')
        
        Please provide the correct information for
        installing Fedora.

Google finds this redhat report which sounds very similar:

        https://bugzilla.redhat.com/show_bug.cgi?id=678414

which claims it's fixed (ERRATA) for Fedora15, but I don't see an
actual solution for Fedora14.

I don't know yet if this problem exists in F16; I'd expect not.

As a workaround I could unpack the ISO into an NFS directory, but I'm
trying to standardize on ISO installs (and not consume 2x the diskspace
for having both packed & unpacked ISO around), so if there's a good fix
for the (presumably) anaconda issue in F14/15, or some other workaround
that allows me to continue with my NFS+ISO methodology, I'd very much
appreciate hearing of it.

Thanks,
sr.