My Belkin router/modem (F5D7632v1 1.00.09 firmware) stopped working wirelessly with my MacBook mid December after a OS X 10.5.1 security update. It works over the LAN and without WPA and WEP security enabled. I have tested my MacBook on another wireless router (BT) with WEP enabled and it works floorlessly. Using another identical Belkin route and I have the same connection issues, i.e. I can get to the router table 192.168.2.1. and no where else using the WLAN, but its fine with the LAN. Other hardware such as iTouch, PSP, iPac and PS3 work fine with the Belkin and WPA security. So it worked without a problem with 10.5.1 and up to the point I installed the last security patch (Mid December time). So from that I have to conclude its a MAC OS X issue, unless I have missed something real basic. Can anyone help me further please?? Thanks and regards David Oh, I have reinstalled OS X with a archive and back-up personal setting, and removed the relative Plists, change the routers IP away from 192.168.*.*., manually set DHCP, but still am unable to connect wirelessly to the intranet.