feisty fawn beta: network manager sets multiple default route

My laptop has two network interfaces, one wired and one wireless.
If I choose the wireless (eth0) via netwok-manager the routing table is the following one:

Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 0 0 0 eth1
link-local * 255.255.0.0 U 1000 0 0 eth0
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
default * 0.0.0.0 U 1000 0 0 eth1

there are two default route assigned.

If then I plug the cable, the network manager switches to wired interface (eth1)
and the routing table is OK:

Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth1
link-local * 255.255.0.0 U 1000 0 0 eth1
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth1

if I choose again wireless interface same problem:

Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
link-local * 255.255.0.0 U 0 0 0 eth1
link-local * 255.255.0.0 U 1000 0 0 eth0
default 192.168.1.1 0.0.0.0 UG 0 0 0 eth0
default * 0.0.0.0 U 1000 0 0 eth1

ProblemType: Bug
Architecture: i386
Date: Fri Mar 30 23:54:01 2007
DistroRelease: Ubuntu 7.04
Uname: Linux ludwig-laptop 2.6.20.4-stefano0 #1 PREEMPT Thu Mar 29 15:51:03 CEST 2007 i686 GNU/Linux