Description of problem:
During FC6->F7 upgrade, anaconda bootloader installation failed with "array
index out of bounds" (can't recall the exact error message) on line #78 of
/usr/lib/anaconda/iw/upgrade_bootloader_gui.py. Stacktrace suggested that
comments on /etc/modprobe.conf were the cause.


Version-Release number of selected component (if applicable): don't know


How reproducible: only tried it once


Steps to Reproduce:
1. start upgrade process
2. choose language and keyboard
3. choose 'upgrade' instead of 'install'
  
Actual results:
Dialog with error message and stacktrace.

Expected results:
Successful bootloader installation.

Additional info:
Booting back to FC6 and removing all comments from /etc/modprobe.conf allowed F7
upgrade to proceeed.