all internet related services crash

[nspmangalore]

one of my friend has an ibm thinkpad.
yesterday, he installed fedora8.
he seems to be having problems with all internet related services.

when he opens firefox or yum with network cable connected, they stop responding.
when the cable is unplugged, firefox is up and responding.
the network manager seems to be working fine.

he is under a LAN which is connected to the internet.
still not able to see others on the lan.
his IP address is assigned thru dhcp.

[RJFUatHOME]

To nail it down further I would try disabling network manager and attempt a static setting (via system-config-network) and see if it works, just choose an address that's probably not being handed out via DHCP.