XP-to-98 internet ok, but not filesharing

I am trying to set up internet sharing and file sharing between an XP
"server" and Win98 "client" using HPNA. Internet sharing works fine,
but file sharing doesn't work at all. What am I doing wrong?

OBSERVED SYMPTOMS
· On the server, My Network Places:Workgroup Computers can see the
client, but double-clicking it results in the error message "Client is
not accessible. You might not have permission to use this network
resource".
· On the client, Network Neighborhood:Entire Network:Workgroup cannot
even see the server.
· Attempts in either direction to map network drives fail with "the
network path could not be found".
· The shared network drives *are* visible using Intel's AnyPoint
Sharing and Mapping application from both directions (i.e, AnyPoint
can see both directions), but attempts to map them fail with "device
is unreachable".

THINGS I HAVE TRIED
· Both machines have the same username (with the same non-blank
password) and are both logged in. This user name has Administrator
privileges.
· The server can successfully ping the client using the IP address,
but fails when pinging it as \\client.
· Net Use fails from the server, whether as Net Use f: \\ipaddr or as
Net Use f: \\client.
· The client cannot ping the server using the IP address. Of course,
Net Use also fails.

THE SERVER
· Win XP Home SP1.
· Internet connection: Cable modem into Intel PRO/100 Ethernet card.
· Internet connection is firewalled using ZoneAlarm. The XP firewall
is turned off.
· LAN connection: Phone network into Intel AnyPoint 10Mbps PCI card.
Running Intel AnyPoint software, updated to ver 2.30.02 (to support
XP).
· C: drive is shared, network users are allowed to share files.
· Client for MS networking, File and printer sharing, IPX, and NetBEUI
installed and bound.

THE CLIENT
· Win 98 ver 4.10
· LAN connection: Phone network to Intel AnyPoint 10 Mbps USB
connection. Running Intel AnyPoint software, updated to ver 2.30.02
(to match server).
· C: drive is shared, network users are allowed to share files.
· Client for MS networking, Family Logon, File and printer sharing,
IPX, and NetBEUI installed and bound.