Comment 3 for bug 368709

The issue seems not to be directly related to Network-Manager but rather to the RP-PPPoE plugin.

I uninstalled Network-Manager, installed Wicd instead, and issued the "sudo pon dsl-provider" command; I am connected now and the connection appears to be stable up to now (about 7 hours total connection time).

I remember I had to install something (probably the equivalent plugin) when setting up Ubuntu (Gutsy) on my computer for the first time but I didn't had to do it again after upgrading to Hardy or Intrepid. Also I must now use the command each time I startup my computer; what should I do to make it be loaded automatically at startup ?

Also, I don't think Wicd is actually working it always indicates "Not connected" in its stauts bar.

Updated additionnal information:

sudo lshw -C network
  *-network
       description: Ethernet interface
       product: 3c940 10/100/1000Base-T [Marvell]
       vendor: 3Com Corporation
       physical id: 5
       bus info: pci@0000:02:05.0
       logical name: eth1
       version: 12
       serial: 00:0c:6e:40:4c:04
       size: 10MB/s
       capacity: 1GB/s
       width: 32 bits
       clock: 66MHz
       capabilities: pm vpd bus_master cap_list ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=skge driverversion=1.13 duplex=half firmware=N/A latency=64 link=yes maxlatency=31 mingnt=23 module=skge multicast=yes port=twisted pair speed=10MB/s
  *-network DISABLED
       description: Ethernet interface
       physical id: 1
       logical name: pan0
       serial: 72:84:05:c0:75:4a
       capabilities: ethernet physical
       configuration: broadcast=yes driver=bridge driverversion=2.3 firmware=N/A link=yes multicast=yes

ifconfig
eth1 Link encap:Ethernet HWaddr 00:0c:6e:40:4c:04
          inet6 addr: fe80::20c:6eff:fe40:4c04/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
          RX packets:24885 errors:0 dropped:0 overruns:0 frame:0
          TX packets:21057 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:28856170 (28.8 MB) TX bytes:5761864 (5.7 MB)
          Interrupt:22

lo Link encap:Local Loopback
          inet addr:127.0.0.1 Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING MTU:16436 Metric:1
          RX packets:404 errors:0 dropped:0 overruns:0 frame:0
          TX packets:404 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:32272 (32.2 KB) TX bytes:32272 (32.2 KB)

ppp0 Link encap:Point-to-Point Protocol
          inet addr:81.247.69.102 P-t-P:81.247.69.1 Mask:255.255.255.255
          UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1
          RX packets:24516 errors:0 dropped:0 overruns:0 frame:0
          TX packets:20683 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3
          RX bytes:28195065 (28.1 MB) TX bytes:5200001 (5.2 MB)

dmesg | grep eth
[ 1.743053] Driver 'sd' needs updating - please use bus_type methods
[ 1.743069] Driver 'sr' needs updating - please use bus_type methods
[ 3.824887] skge eth0: addr 00:0c:6e:40:4c:04
[ 9.896755] udev: renamed network interface eth0 to eth1
[ 29.200468] skge eth1: enabling interface
[ 29.204556] ADDRCONF(NETDEV_UP): eth1: link is not ready
[ 31.467419] skge eth1: Link is up at 10 Mbps, half duplex, flow control none
[ 31.467592] ADDRCONF(NETDEV_CHANGE): eth1: link becomes ready
[ 41.496008] eth1: no IPv6 routers present

cat /etc/network/interfaces
auto lo
iface lo inet loopback

cat /etc/NetworkManager/nm-system-settings.conf
[main]
plugins=ifupdown,keyfile

[ifupdown]
managed=false