Disabled AirPort when sharing Ethernet???

I can't seem to figure out why but all of a sudden I can no longer share my Ethernet connection via the AirPort. As soon as I enable sharing, my AirPort disables and I cannot re-enable it or find it via wireless. In order to use my AirPort again I have to reboot. I've shared my connection this way many times and the only things I've installed recently were updates from Apple. But I've used sharing since the last update so technically nothing has changed (from what I can tell) in the last few days.

Any ideas?

No one has any idea at all???

I had something like this together with other problems when trying to share my internet connection to other devices via Airport.
Now instead of Internet Sharing I'm using these scripts:
sysctl -w net.inet.ip.forwarding=1
natd -interface ppp0
ipfw add divert natd ip from any to any via ppp0

this is specific for a modem ( ppp0 ), in your case I think you have to change ppp0 to en0
Only precaution: any time the internet connection is dropped you have to run:
ipfw delete 100
before to reestablish it