SNMP v3 Opmanager and Nortel/Avaya

SNMP v3 Opmanager and Nortel/Avaya

Hello,
I have over 200 Nortel/Avaya switches, mix of 5500 and 8600.
I am moving all these to SNMP v3 as part of our PCI compliance.
I have created new credentials in Opmanager to reflect v3.
When i update a device with the new credentials, it fails , when i try to "rediscover now" again it fails.
the only way i seem to be able to get Opmanager to use V3 credentials correctly is if i remove the device using RemoveDBEntries.bat, restart Opmanager Server and re-discover the device.Then it works fine on v3.
With over 200 devices that have built up data and stats for a number of years, removing them and readding them is not a option.
How can i fix this in the easiest way possible.
 
thanks

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