nic acquires ip in the same range as the other nic ip when ics is enabled

I have ICS enabled on a host computer running windows XP. the external d-link NIC is connected to a cable to the internet throught PPPoE (user name and password). when connected the external nic aquires an ip 172.0.4.156 in normal functioning.

The internal RTL 8139d NIC is set as the internal network. with ip set manually to 192.168.0.1.

and the internal NIC is connected to Dir-300 router configured to obtain connection dynamically from ICS dhcp. afterwards my laptop running vista gains access to the internet through the wireless router -> through ICS host xp computer. ( I have done this because I couldnt connect my router to the internet through pppoe although the router has pppoe capability).

now the problem is after using internet for a while and when I restart my xp host computer. the external nic becomes problematic. acquiring an ip of 192.168.0.128, in the same range as the internal network ip. the amazing thing is when I connect to pppoe it connects normal. and internet connection is valid on the same computer.

the problem is my laptop losses access to the internet while remain connected locally. to restore the connection you need to restart the wireless connection. then you gain access for a while then you lose it. and so forth.

I have tried uninstalling/reinstalling the drivers on the xp host computer but the external kept aquring the same ip address.I have tried to disable ics and enable. deleted the pppoe connection and reconfigured it along with ics.

any one has an answer please. or an idea on how to make the router connect to the internet through pppoe. this would solve all the problems.​