I can produce both errors mentioned here, the -14090 (eDSAuthFailed) error when trying to add my AD domain under Directory Servers and the 'Invalid user name and password' when trying to bind under Services. I have had the same experience on 2 brand new MBP's, one was upgraded from Tiger to 10.5.0, the other was a clean install.
I have managed to now get the machines to bind to AD, but the problem is not resolved, I'd like to highlight what I did to get an AD bind as others might like to try this.
After experiencing all the issues spoken of in the thread, I tried creating the computer account in AD manually. In the Directory Access utility, I then tried to add my AD domain under Directory Servers, using the computer name I had just created, I got a message warning me that the computer account already exists and confirm that I wanted to use the existing account, said OK and the domain was added. However, I was still unable to login to the machine using my AD credentials but I can access SMB shares by manually entering my AD details.
From reading the (many) forums on this issues, it strikes me that the Directory Access v1.6 in Leopard does not seem to ever create the computer account in AD - I.E. Machines that were already talking to AD prior to a Leopard upgrade do not seem to be affected in the same way. Some users are still having AD issues (such as can't login) but the machines that were in AD before seem to bind OK, that is they maintain the AD status they had under Tiger.
Also, I was unable to perform the bind as described above while using the root administrator account for AD, though it work fine with my account (also Domain Admin). The only glaring difference I can think of is that my administrator account has a space in the password. Anybody else come across this issue?
I am in the process of trying this:
+Toni Weurlander of Finland isn't having any problems with Leopard 10.5.1:+
+I just installed a new MBP freshly with Leopard, updated it to 10.5.1 and bind it to our AD. Everything just worked like it did on Tiger. Never tried to bind it with 10.5.0. All SMB shares seem to work as expected.+
The above is from -
http://www.macwindows.com/leopard.html#102907i
Will let you know how it goes.