Suddenly failed to connect

[David Bowskill]

Dear Ubuntu Users
My wife and I share a four port router and we both are running 10.04
My Internet connection is fine but she is now receiving 'unable to
connect to server'

There is no hardware fault as the machine is dual boot and MSwindows
connects OK
I have checked /etc/resolv.conf and that is fine.
Ran pppoeconf but could not make any sense of the output ( it opened a
ncurses window, did some scanning and reported on both machines aid on
both machines that it could not connect - obviously wrong on mine).
Then ran  "ifconfig -a" on both machines the results are as below:
                *******************************
Machine NOT connecting:

simone at simone-computer:~$ ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:0f:ea:de:1c:47 
          inet6 addr: fe80::20f:eaff:fede:1c47/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:33 errors:0 dropped:0 overruns:0 frame:0
          TX packets:12 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1980 (1.9 KB)  TX bytes:636 (636.0 B)
          Interrupt:19 Base address:0xd800   <--- not in my file as
below????

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:318 errors:0 dropped:0 overruns:0 frame:0
          TX packets:318 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:58073 (58.0 KB)  TX bytes:58073 (58.0 KB)

simone at simone-computer:~$
                ********************************
Machine connecting OK:

david at DJB-P4:~$ ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:20:ed:5f:47:56 
          inet addr:192.168.1.33  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::220:edff:fe5f:4756/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:14339 errors:0 dropped:0 overruns:0 frame:0
          TX packets:13881 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:11667495 (11.6 MB)  TX bytes:1505608 (1.5 MB)

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:280 errors:0 dropped:0 overruns:0 frame:0
          TX packets:280 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:24602 (24.6 KB)  TX bytes:24602 (24.6 KB)

vboxnet0  Link encap:Ethernet  HWaddr 0a:00:27:00:00:00   <---- not in
file above, what is this ?????
          inet6 addr: fe80::800:27ff:fe00:0/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:0 (0.0 B)  TX bytes:804 (804.0 B)

david at DJB-P4:~$ ifconfig -a
                    ***************************

I have been struggling with this for some time but no joy.
Help would be greatly appreciated.

Thanks
David