Exchange ESE97 logs

I recently noticed that the ESE97 EventLog messages were missing the description info on our Exch5.5 on Win2k system. They did appear origionally and I’m suspecting our AV upgrade. On checking an older server I noticed the reg key HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\EventLog\Application\ESE97 points to the System32\ESE.dll. On the newer problem system it points to System32\RealEse.dll. This is a different install so it may be a vallid entry but the RealEse.dll file doesn’t exist while the ESE.dll does. Anyone ever heard of it?