I have a machine on my network that refuses to sync our Gpupdate. I am getting error code 1006 error code 49 which points to bad credentials but I am using the same user that I would on any other machine with out and problems (same AD, DC etc...). Any ideas? The user gpupdate succeeds, the computer fails. I also get this error "The processing of Group Policy failed. Windows could not authenticate to the Active Directory service on a domain controller. (LDAP Bind function call failed). Look in the Details tab for error code and description."
Group Policy runs within the Winlogon.exe process, which runs under the LocalSystem security context, so this is not about what user is logging on to the computer, this is about the computer.
The only suggestion I have would be to unjoin and rejoin this computer to the domain to see if that corrects it.