tor 0.1.0.17, router_mark_as_down(): We just marked ourself as down. Are your external addresses reachable?

[jensmh at gmx.de]

After upgrading from 0.1.0.16 to 0.1.0.17, i get the following warning/error message:

Tor: router_mark_as_down(): We just marked ourself as down. Are your external addresses reachable?

There is no packet filter running and tor seems to accepting incoming connnections.
Is this a tor bug?

Thanks.