Trouble with second IP on same nic

[sheslostcontrol]

OS: RHEL 5.3
Poweredge 2490 server

Currently have a single cable running into one nic card (eth0). For the past two years this was configured to handle two IPs under eth0:

1.1.1.1 and 
1.1.1.2

Tonight I discovered that 1.1.1.2 no longer works. Pinging 1.1.1.2 fails, even though the profile is checked and activated under Network Configuration in the gui. Pinging 1.1.1.1 returns satisfactory replies.

x  Active  eth0 live         Ethernet   [1.1.1.1]
x  Active  eth0 dev Ethernet   [1.1.1.2]

Both IPs are static, and the IP Address Settings are identical (except for the address) across both profiles:

nick: live
Address: 1.1.1.1
Subnet Mask: 255.255.222.0  (This is the correct subnet mask, as 1.1.1.1 works fine)
Default Gateway: 1.0.0.1

nick: dev
Address: 1.1.1.2
Subnet Mask: 255.255.222.0
Default Gateway: 1.0.0.1

No routes are configured and both profiles are configured for hardware device eth0.

Suggestions on where to look next?

[sheslostcontrol]

Here are the raw ifcfg files for each profile.

live

[network-scripts]# more ifcfg-live
# Broadcom Corporation NetXtreme II BCM5708 Gigabit Ethernet
DEVICE=eth0
BOOTPROTO=none
HWADDR=00:00:00:00:00:00
ONBOOT=yes
DHCP_HOSTNAME=sub123.web.site
IPADDR=1.1.1.1
NETMASK=255.255.222.0
GATEWAY=1.0.0.1
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes

dev

[network-scripts]# more ifcfg-dev 
GATEWAY=1.0.0.1
TYPE=Ethernet
DEVICE=eth0
HWADDR=00:00:00:00:00:00
BOOTPROTO=none
NETMASK=255.255.222.0
DHCP_HOSTNAME=sub123.web.site
IPADDR=1.1.1.2
ONBOOT=yes
USERCTL=no
IPV6INIT=no
PEERDNS=yes