Getting "SNMP error" shown at the top of the device page

[xblanch]

We have a new Cacti install and are testing with one Alcatel-Lucent OS 6450-P24 and we are having dificulties getting SNMPv3 working. We have tested snmpget on the command line, for example:

snmpget -v3 -a SHA -xDES -uuser -Aourpass 192.168.161.240 interfaces.ifTable.ifEntry.ifSpeed.1002

This works perfectly.
In the device config we have configured in the SNMP options: SNMP Version = 3, SNMP Username, SNMP Password, auth protocol = SHA, privacy protocol = DES with default port and timeouts. We are getting "SNMP error" shown at the top of the device page and no other information as to what is the problem. We haven't found any relavent information in the logs to know what cacti is doing different than we are when running snmpget manually so if anyone can help debug this or if they know what might be causing the issue any help would be appreciated.

Software versions are:

CentOS 6.5
PHP 5.3.3
php-snmp-5.3.3
net-snmp-5.5-50
Cacti 0.8.8c