I'll bet the ADR function isn't your problem. I've used ADR extensively and have never seen it execute when it's been told not to.
If you really want to clear out ALL of the settings in a DeviceNet scanner, put the PLC in Program Mode and us RSNetworx for DeviceNet's "Class Instance Attribute" editor to send a Service 0x05 (Reset) to the device (use Class 1, Instance 1, Attribute 1). This will totally clear the flash memory of the scanner and reboot it as Node 63, 125 kb/s.
That method works with all the A-B scanners; 1747-SDN, 1756-DNB, 1788-DNBO, 1769-SDN, etc.
Remember that ADR sets all paramters to their saved settings. Are you sure that all the parameters are being changed, or are just some of them changing ? There might be an explicit message or PanelView that you aren't taking into account.
I have seen 160-DN2 interfaces default some of their configuration parameters (specifically the I/O assembly parameters) when very large electrical disturbances took place. Specifically, we had a 1000+ volt static discharge from an ungrounded conveyor belt being routed to ground through the DeviceNet shield.
