I don't know if the following will help. Apparently, the 10.5.6 upgrade genrated some problems amongst many things, some difficulties with airport with some users. One explanation is that the automatic update was not fully complete even though it appeared so. Downloading the seperate combo update was suggested in an article I read today. The following is a paste from MacFixit about some other possible fixes:
Some users are having problems connecting to wireless networks after applying Mac OS X 10.5.6. Some have
described Airport Extreme connections dropping out, and others have suspected either WEP or WPA protection
being the culprit. However, in most cases these problems seem to have self-corrected after a while of usage. As
such, it is recommended to restart the computer when this problem happens, and perhaps also run permissions and
disk repairs with Disk Utility. Additionally, try resetting the wireless routers the computer is connected to, in order
to refresh the connection and IP address lease information in the router.
Some users might get an error claiming no AirPort card is installed, but resetting the PRAM in the computer seems
to clear this problem up. "
another fix suggested to reinstall the Airport Utillity:
"As reported yesterday, some people are experiencing problems with the installation
rocess for the Mac OS X 10.5.6 update. Although Software Update presents the
appropriate update file, many users are experiencing hangs resulting in the update
never completing. As also noted yesterday: for some users, this occurs during the
"configuring setup" step, and the system never goes into the actual update mode. Other
users have reported errors stating the update cannot be installed because it encountered an error, as well as
"validation" errors for the update files. For the most part, these problems have occurred with the delta updater.
Fix For most of these situations, users can fix the issue by downloading and applying the standalone "Combo"
update. This edition includes all updated files since the release of 10.5.0, and as such will ensure all files are
properly accounted for in the system. It is recommended that users update by downloading the combo update and
then boot into Safe mode. When in Safe mode, run a permissions fix and drive check using Disk Utility, and install once those are completed."
Last edited by toby2; Jan 9th, 2009 at 08:02 PM.