I was also working this issue with the Network team here (the router and firewall folks). One of them found that the default gateway was not being picked up from /etc/sysconfig/network/routes. He had me run 'netstat -rnv' and it displayed:

wcs-mf-winxs-db2p:/tmp # netstat -rnv
Kernel IP routing table
Destination     Gateway         Genmask         Flags   MSS Window  irtt Iface U         0 0          0 eth0
He then had me temporarily add a gateway by issuing 'route add default gw'. I was then able to PuTTY into the server.

Any idea how to make this permanent (i.e. without coding a script to issue the command at boot time)? I will continue to research how to accomplish that.