Problem Mapping Drive On Replacement Windows 2000 Server

We just had to replace a Windows 2000 server that crashed. We built up
a new
server using different hardware, but kept the same hostname and IP
address
as the old one.

We have several XP Pro workstations and a few Windows 98 machines on
this
network. The XP machines all talk to this replacement server just fine,
but
the Win98 machines won't connect to file shares, won't browse the new
server, etc. We need to map a network drive to this replacement server
for a
critical application to run correctly, and this isn't working on the
Win98
machines.

I figured out that it's an ARP problem...the Win98 machines can ping
the
replacement server, and the name resolves to the IP address (so this is
not a DNS
issue). The MAC address is the only thing that has changed.

If I run the following command on the Win98 machines:

arp - s "server_ip" "new_mac_address"

then enter the IP address in Windows Explorer, it will work properly
for
about 24 hours...then we have to repeat this every morning to get these

machines to connect.

Is there any way to resolve this so these older machines will work
properly
with this replacement server and remember the changes?

Thanks,

Donnie