Reproduced with virt-manager-0.9.0-5.fc16.noarch during Fedora Virt Test Day:

https://fedoraproject.org/wiki/Test_Day:2011-09-15_Virtualization

This is fixed upstream, just need to backport:

http://git.fedorahosted.org/git?p=virt-manager.git;a=commit;h=a815fa17a7c643ddde8ea326399e2bee449dff98

virt-manager-0.9.0-6.fc16 has been submitted as an update for Fedora 16.
https://admin.fedoraproject.org/updates/virt-manager-0.9.0-6.fc16

Package virt-manager-0.9.0-6.fc16:
* should fix your issue,
* was pushed to the Fedora 16 testing repository,
* should be available at your local mirror within two days.
Update it with:
# su -c 'yum update --enablerepo=updates-testing virt-manager-0.9.0-6.fc16'
as soon as you are able to.
Please go to the following url:
https://admin.fedoraproject.org/updates/virt-manager-0.9.0-6.fc16
then log in and leave karma (feedback).

virt-manager-0.9.0-6.fc16 has been pushed to the Fedora 16 stable repository.  If problems still persist, please make note of it in this bug report.