Tor browser doesn't recognize change of network interface which provides internet

When there're two network interface available which both provide internet access and one connection is dropped (cable unplugged) and the other is established, Tor browser uses 100 % of one CPU core until the connection times out (after ~2 minutes). It only succeeds randomly to recognize the new connection. firefox 36.0.1 has no problem dealing with that situation.

experienced with Tor browser 4.0.4 on Ubuntu 14.10 amd64 with Linux 3.19.1

Trac:
Username: krichter