1) Backup the current ibmlan\services\netlogon.exe
2) Stop the Netlogon service and copy the provided Netlogon.exe
3) Add a new parameter NetlogonQuiet = YES to the ibmlan.ini [browser] section only.   
4) Clear the error log file. 
5) Start the Netlogon service. Recreate the problem amd check if the NET3215 error messages are logged.