You can check this and verify you have 2 entries.
Make a backup of db2. Then you can delete the new one with the command:
remove from ssc.deployments where depid='xxx'
where the depid is what you saw for the entry of type "com.ibm.lotus.sametime.systemconsoleserver" and a OffVersion of 188.8.131.52 in the xml from the linked post. Then double check you're settings in console.properties and productConfig.properties and run the registerProduct.bat -upgrade again. If you're settings are right, it won't create a 2nd entry but will update the first.