no internet on 9.04

[Ziv Kohav]

After a clean install of Ubuntu 9.04 on a new partition I configured pppoeconf and internet worked fine. Once I rebooted the internet was gone and running pppoeconf again did not help. On 8.10 and Windows XP, on other partitions it works fine.
Here is the output of ifconfig on 9.04 following by ifconfig on 8.10 for comparison. I'd appreciate your help- I reinstalled so many times trying to understand why this happens without success.

IFCONFIG on Ubuntu 9.04 (no internet)

eth0 Link encap:Ethernet HWaddr 00:e0:4d:2b:f9:ca
inet6 addr: fe80::2e0:4dff:fe2b:f9ca/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:10 errors:0 dropped:0 overruns:0 frame:0
TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:600 (600.0 B) TX bytes:1132 (1.1 KB)
Interrupt:252 Base address:0xc000

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:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:16 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:1184 (1.1 KB) TX bytes:1184 (1.1 KB)

ppp0 Link encap:Point-to-Point Protocol
inet addr:87.68.39.54 P-t-P:87.68.32.254 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1
RX packets:3 errors:0 dropped:0 overruns:0 frame:0
TX packets:3 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:54 (54.0 B) TX bytes:54 (54.0 B)

IFCONFIG on Ubuntu 8.10 (internet works fine)

eth0 Link encap:Ethernet HWaddr 00:e0:4d:2b:f9:ca
inet6 addr: fe80::2e0:4dff:fe2b:f9ca/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:110225 errors:0 dropped:0 overruns:0 frame:0
TX packets:85154 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:155148204 (155.1 MB) TX bytes:7159457 (7.1 MB)
Interrupt:252 Base address:0xc000

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:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

ppp0 Link encap:Point-to-Point Protocol
inet addr:77.125.129.61 P-t-P:77.125.128.254 Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1492 Metric:1
RX packets:110175 errors:0 dropped:0 overruns:0 frame:0
TX packets:85098 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:152721294 (152.7 MB) TX bytes:4943093 (4.9 MB)