If you’re 10.4.11 and use AD integration, please read

So we've been having weird SMB errors like people not being able to connect, some people connect one day and the next they can't, etc. in our Golden Triangle. After much trial and error, it seems that the AD plugin in 10.4.11 is buggy and can be swapped with the AD plugin from 10.4.10 or 10.4.9. Make sure you use the same architecture as well when swapping. So if you have people with SMB errors after updating to 10.4.11, please swap the plugin. It won't hurt at all and I think you may see things working again. Please try at your own risk though. And backup the 10.4.11 plugin before you replace it with the 10.4.10 one. The plugin can be found at /System/Library/Frameworks/DirectoryService.framework/Resources/Plugins/Active Directory.dsplug/Contents/MacOS/Active Directory After swapping, you'll want to sudo killall DirectoryServices