Question : trouble demoting a dc

I have 2 DCs, I'm trying to demote one.  When I do it prompts me for a new password.  After I enter one the wizard fails and says

The operation failed because:

Managing the network session with dnspokey.tpai.local failed

logon failure:  the target account name is incorrect

Answer : trouble demoting a dc

i forced it b/f i saw your new reply.  i'm waiting for the raid array to rebuild and then i'm going to restart, hopefully all is well.