ospf uses private ip as a gateway

Hi. I'm using bird 1.2.5 from debian squeeze respository. I've got two routers with public a private ip addresses on the connecting interfaces. The public addresses are selected as primary in device protocol but ospf chooses private address as the address to route prefixes over. When I block ospf packets from the private addresses it switches fine but when I allow ospf to them it switches all the routes to the private gateways again. Is there any way to force bird to use public addresses other then setting them as primary in device protocol specification? I want to keep interface names in interfaces definitions instead of ip addresses. thanks for your help mk