Belkin Wireless Network Problems

Hi All
I am having real snags setting up the following:
I have a PC using XP Pro, and a laptop using XP Home (both SP2) that i
would like to set up both in a wireless network using the following
cards and router/modem I have bought:
1. Belkin 802.11g wireless Notebook Network Card
2. Belkin 802.11g Desktop Network Card
3. Belkin 802.11g ADSL Router/Modem - F57630-4A

I connected the router to the mains and the phone line and got the
lights I was expecting from the manual.
I installed the network cards successfully into both the PC and laptop
successfully. From the PC I logged into 192.168.2.1 for the router
interface, and set the parameters needed.
However, after about 5 minutes, the router seems to lock and I cannot
navigate the router anymore. I reinstalled the network card, and reset
the router and was able to reconnect to the router but the same thing
happened after about 5 min again.
I then did the same from the laptop, and after about 5 minutes the
same thing happened.
When I tried 192.168.2.1 from the pc, i got a "Duplicate
Administrator" error and was unable to connect to the router
interface, even when the laptop was powered down.
Also, when I log out from the laptop or the PC, and login again, the
connection to the network is lost, and cannot be reestablished until I
reinstall everything again.
For info, at the moment, both the PC and the laptop are right next to
the router.
Also, with respect to the parameters, I can see where to enter the ISP
username and password, but nowhere to enter the Server IP address or
subnet masks.

Any help here please would be very much appreciated. I am going to try
another router, but do wonder if this is the problem.

Many thanks in advance

Matt