Failure Audit – Event ID 565

We have a mixed-node W2K-NT domain. There are two W2k domain controllers and two older NT4 BDCs. We also have several W2K member servers one of which is generating Failure Audit – Security – Directory Service Access Event ID 565 for the manchines account (WEB2K$). I can’t find any usable information on what this Event ID means or how to handle it. All systems are up and running with out any percieved problem but the security event log on the W2K Domain Controller acting as PDC is full of 565 events