AirPort fails to connect to existing networks after Repairing Disk Permissions

Question

So my system was running a slower than normal, and I started poking around and found that Disk Utilities provided buttons to verify and repair permissions and disks. I chose to verify both and learned nothing was wrong with the disk, but the permissions on system files were reported as incorrect. I pressed the Repair permissions button and felt happy about the successful report (though a bit ignorant about why system files had ever fallen into dis-repair). I do recall noticing that AirPort folders and files within those folders had write permissions and Verify reported they should not. So, those were apparently changed to read only.

Now, I come in to work this morning and find I can no longer connect to wifi networks that I added long ago. I also cannot join new ones. If the connection doesn't time out while trying to set it up, I get a dialog saying that the network requires a password. Entering the password causes it to show a busy animation, and then it pops up again with the same message. Soooo I'm guessing that the Repair permissions turned writable files into read only files and some of those files stored network information like passwords or authentication of some sort. I've been perusing the web and apple's forums and though I've found reports of similar timeouts and error messages, no one has correlated the problem to repairing permissions. I'm fairly sure of the correlation. Can someone help resolve the problem?

The Console shows lots of messages like this:

... Apple80211 framework[191]   Scan() error -3905 (Timeout)
... Apple80211 framework[191]   __performScan() failed (-3905)
... Apple80211 framework[191]   airportd MIG failed (Associate Event) = -1 (Unknown error)  (port = 50735)
... System Preferences[191] Error joining private_sid: Connection failed (-1 result unavailable)
... kernel  AirPort: Link Down on en1. Reason 1 (Unspecified).
... airportd[95]    Apple80211Associate() failed -3905 (Timeout)
... Apple80211 framework[149]   airportd MIG failed (Associate Event) = -3905 (Timeout)  (port = 64615)

Answer 1

The issue is only coincidental, reboot the machine and see if it will join wireless networks again. I have had the issue many times on various Macs.

Your passwords for wireless networks are stored in the keychain and would not be affected by anything being set incorrectly in the Airport folder.

Usually, disk permissions are incorrect because an application installer or application itself that modified the permissions. Disk utility refers to a master list that has all the correct permissions and then ensures that system files and applications that were installed via an Apple installer have the correct permissions to function properly.