Reseting Unit-ID on nanoBTS

Hello, I have a nanoBTS from ipaccess. I used ipaccess-config to set the Unit-ID of the nanoBTS and also the Primary OML IP address. Everything worked OK and OpenBSC and the nanoBTS where communicating. My problem now is that I want to connect the nanoBTS back to my original BSC (from Zynetix). By using ipaccess-config I set the OML IP address back to what it was originally but the unit does not connect to the original BSC. I have two other nanoBTS's and their Unit-ID is 65535/255/255 before they 'sign up' to the BSC, where they get another Unit-ID. I've tried using ipaccess-config to set the Unit-ID to that value but get an error: "Failure to set attribute. This seems fatal" Does anyone know how I can reset the Unit-ID to 65535/255/255 ? Best regards, Bjarni S. Sigurdsson