I copied this from macfixit:
Troubleshooting (pulled) Mac OS X 10.2.8 (#3): Detailed Ethernet instructions; MOTU; more
Ethernet problems On Tuesday, we reported a fix for the loss of Ethernet functionality experienced by some users who installed the 10.2.8 update. The fix involved booting into OS 9 to replace the 10.2.8 version of AppleGMACEthernet.kext (v1.3.0) with the 10.2.6 version (v1.2.4). For those who have Macs that can't boot into OS 9, we mentioned that you would need root access to replace the file. Here are more explicit instructions on how to perform this procedure from within OS X:
1. Download/extract/restore the earlier version of the AppleGMACEthernet.kext file (we provided a link to a copy of the file yesterday).
2. Launch Terminal from within an admin-level account, and type sudo -s (Provide your account password when prompted.)
3. Type cd /System/Library/Extensions and press the return key.
4. Type rm -rf AppleGMACEthernet.kext and press the return key. This deletes the newer, problematic kext file.
5. Type mv (be sure to include a space after the "mv"). Do not press return/enter yet.
6. Drag the older AppleGMACEthernet.kext file (the one you just downloaded/extracted/restored) into Terminal. The path to the kext file will be automatically typed for you. Do not press return/enter yet.
7. Press the space bar once, and then type /System/Library/Extensions/AppleGMACEthernet.kext and press the return key. This executes the command, which moves the older kext file into the Extensions directory, replacing the newer (problematic) version.
8. Type cd /System/Library and press return.
9. Type rm Extensions.kextcache and press return.
10. Type rm Extensions.mkext and press return.
11. Immediately restart your computer.
Note that some users report getting a message after the restart that the file is "incompatible and could cause security problems." Clicking the "Fix and Use" button and restarting will allow full functionality.
Network problems due to DHCP issues One common problem users have experienced after installing the 10.2.8 update is a loss of connectivity on computers that obtain their IP address via DHCP. A number of users have found that requesting a new lease restores connectivity. An easy way to renew your DHCP lease is the utility Cocktail; choose the Network screen, click the DHCP tab, and then click the Request button.
File Mappings reset Many users report that the 10.2.8 update "reset" some or all custom file mappings. For example, if you had previously used the Get Info window or Finder contextual menus to change the application used to open a particular type of file, the 10.2.8 update may have caused OS X to "forget" those settings and revert to the default setting. Unfortunately, the solution seems to be to re-select your chosen application for each type of file that was affected.
TransparentDock update (and recovery) If you use the utility TransparentDock to modify Dock behavior and/or appearance, you need to update to TransparentDock v2.1 before modifying the new Dock. (The 10.2.8 update installs a new version of the Dock application, so you'll lose your previous modifications.) Modifying the Dock with previous versions under OS X 10.2.8 can result in an inability to launch the Dock. If you've already used an older version and cannot launch the Dock, the solution is to restore the original Dock from a backup. If you don't have a backup, you can use the utility Pacifist to extract a clean copy of the Dock application from the 10.2.8 Update package. (Open the installer package in Pacifist, select /System/Library/CoreServices/Dock.app in the Pacifist browser, and click the Install button.)
Sleep problems due to Energy Saver settings Several MacFixIt readers have reported an inability to wake from sleep since installing the 10.2.8 update. David Blangstrup wrote back to say that, for him, having the Energy Saver settings set to "never" go to sleep was the cause -- changing the setting to a definite amount of time (such as two hours) prevents this "deadly" sleep.
10.2.8 Installs Flash 6 plug-in, overwriting Flash 7 plug-in if installed A number of users have reported that installing the 10.2.8 update installs the Flash 6 browser plug-in (in /Library/Internet Plug-Ins), overwriting a later version, if present. If you had previously installed the Flash 7 plug-in, you'll need to reinstall it after applying the 10.2.8 update.
Audio problems with MOTU interface and other audio apps Some users who have updated to 10.2.8 are experiencing kernel panics when MOTU devices are connected. MacFixIt reader Logan Susnick reports that she received the following fix from MOTU that alleviated these problems:
1. Log in as an admin-level user.
2. Disconnect all MOTU devices.
3. Launch Terminal and type sudo rm -R /System/Library/Extensions/MOTUFireWireAudio.kext and press the return key. (Provide your account password when prompted.) This deletes the existing MOTU driver.
4. Reboot.
5. Reinstall your MOTU drivers (version 1.0.5, available from the MOTU website).
In addition, some users report that their Griffin iMic no longer works. Other users report that they cannot change audio input/output settings. Others report that using audio applications such as ProTools and WireTap results in distorted sound. Are you having audio problems?
Hopefully the above is of some help.
