I have found that the only way I can ever get networking to function correctly on my systems is to
yum erase NetworkManager
with NM installed it insinuates tentacles into everything, doing stuff like grabbing control of USB network devices when I plug them in (devices I don't want it fooling with).
Now, yum has just reinstalled NetworkManager because new dependencies dragged it in. When I remove it, all this new junk goes with it:
Removed: NetworkManager.x86_64 1:0.9.4.0-9.git20120521.fc17
Dependency Removed: NetworkManager-gnome.x86_64 1:0.9.4.0-9.git20120521.fc17 control-center.x86_64 1:3.4.2-4.fc17 gnome-bluetooth.x86_64 1:3.4.2-1.fc17 gnome-shell.x86_64 0:3.4.1-6.fc17 orca.x86_64 0:3.4.2-1.fc17
Most of those things didn't depend on NM previously, why do they depend on it now? Why should I need to have NM installed just to get to the audio volume control (for example).