LDAP BIND Problem with Exchange 2003

I am running a Mixed mode Exchange environment with one Exchange 5.5 server on NT4 SP6 and one Exchange 2003 server on Windows Server 2003 in a Windows 2000 Native Mode AD Domain. I have one AD Forest with 3 root domains, not child domains. The Exchange servers are in the root of the forest with ADC connection agreements going to the other domains. I am getting the following error: It is event ID:8026 Source: MSADC
LDAP Bind was unsuccessful on directory sapps.smyrna.local for distinguished name ‘SMYRNA\Administrator’. Directory returned error:[0x51] Server Down. (Connection Agreement ‘Users: smyrna.LOCAL – M-TEKINC\m-tekinc’ #3144)

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I can’t seem to resolve this error. Any assistance would be greatly appreciated. Thanks in advance.