Connection problem

I live in a very long house so the system is as follows:
Rear of house
Bigpond standard modem to Dlink DI524 router. This router is set to assign all IP addresses dynamically. Two laptops (1 xp and 1 Wn98) connect to the router wirelessly.
Also connected to the DI524 by cable is a Dlink AP2000 set in bridging mode.

Front of house
Dlink AP2100 which picks up the signal from the AP2000 at the rear. 2 desktops are connected wirelessly to this (AP2100)

I've run latest Spybot and Avast software and also Ccleaner.

All computers are set to
SSID default
IP dynamic
Gateway 192.168.0.1
Subnet 255.255.255.0

Everything has been running fine for a couple of months. (file/printer sharing and internet etc.)

My problem is that one the front computers (Win98) now won't connect to the internet. It sees & connects to all the other computers but when I ping the modem (10.0.0.138) there is no response. I've used winipcfg to renew the lease to no avail.

Any ideas ?

My problem is that one of the desk

 

Im a bit confused. Where does the 10.0.0.83 address come into play if your default gateway is 192.168.0.1? Are you natting using the 10.x.x.x range as your inside DHCP scope? Your default gateway should be your routers IP address and if it is 192.x.x.x then unless you NAT, you will go nowhere. How are you configured, the other PC's etc.

Rick