Description of problem:
Summary:  DHCP install works.  Non-DHCP install causes exception, when clicking
on the 'Fedora Extras' checkbox on the Repositories screen.

Machine:  ICH7 Intel SDV box.

Baseline:  FC6 x86-64 DVD install completes successfully, when using the default
(100% DHCP) network settings.

Problem case:  FC6 x86-64 DVD install crashes with a Python exception. 
Variation from baseline:  (a) entering a manual IPv4 address, netmask, primary
DNS server, and gateway.  IPv6 checkbox is unchecked, disabling IPv6.

Version-Release number of selected component (if applicable):
FC6 GA

How reproducible:
Always.

Steps to Reproduce:
1. Enter manual IPv4 address/netmask/gateway/DNS, rather than using DHCP.
2. Un-check the IPv6 checkbox, disabling IPv6.
3. Proceed through screens, until you reach the Repositories screen.
4. Check the Fedora Extras checkbox (which initiates the
activate-network-interface dialog).
  
Actual results:
Python exception, installer crash, kernel halt.

Expected results:
Installation proceeds, like it does with the all-DHCP install.