My network is as follows - Static IP addresses:

Gateway: M1122 192.168.1.254
Wireless Router: DI-524 192.168.1.1

Workgroup: PRODSYS
ADVANTAGE computer: 192.168.1.2
dell computer : 192.168.1.4

Subnet Mask : 255.255.255.0

Both computers list PRODSYS as the Primary DNS suffix

ADVANTAGE Node type is Hybrid while dell is Broadcast

dell is Win2k
ADVANTAGE is XP Pro

From the ADVANTAGE I can ping all ip addresses.
From the dell I can ping all EXCEPT the ADVANTAGE (192.168.1.2)

From the ADVANTAGE I can ping nothing by name except ADVANTAGE
From the dell I can ping dell and M1122 by name (I'm not sure of the Name of DI-524)

Both computers can use the internet but cannot see each other.

Can anyone suggest where to look, please?