I have a Belkin Router and Belkin Access Point. I have set up WEP 128Bit security, disabled SSID broadcast, "ANY" SSID access, disabled DHCP, changed the IP range from the default and limited the IP range. Also, included MAC address filtering.

However with all of this in place I'm still seeing in the ISP log activity outside of the hours of use.

All PCs are switched off when not in use. The wireless network is still active. I have unplugged the ADSL line and found on those days that no activity in the log. Therefore, I consider that the breach is via the wireless router.

I have read that the MAC address can be spoofed and WEP can be broken, but how can they get hold of the IP range?

What else can I be missing? How do I know that I have the correct MAC address for my devices?

Any help and advice would be appreciated.

Well to anser to your question YES it can be EASILY Broken, If you want to test out the security of your "flawless" network......

here is a nice video + tutorial to show you how to test the security (if you can call it security) of your WEP network.

http://www.tuto-fr.com/en/tutorial/tutorial-crack-wep-airc rack.php

I'm having this exact same problem but with WPA

Is there any way to solve it? The intruder just waltzes through new passwords and settings like an open door

Thanks!