Posted 16 February 2010 - 10:03 PM
OK, this is a curious one. I would have thought a problem with a real-time clock messing up key rotations on WPA, but the fact it works with the IP address pretty well debunks that one. So we are looking at a DNS problem that dies every 5 minutes. If you could, check ipconfig \all while it is broken, then do the release and renew and ipconfig \all again. Compare to see what the DNS entries say. Are they the same ? Is it gone entirely when it's broken ? Your DHCP lease lifetime should be much more than 5 minutes, but you might check. Look at the system log too, to see if you somehow got a DHCP Revoke packet in there.
On a side note, are you or have you ever run Norton on this machine ? It has a nasty habit of blacklisting your DNS host under some conditions, but then it shouldn't work at all.
Your DNS settings are set in the Linksys Profile setup, and should be editable there. It's under Manual Setup on the Available Wireless Networks page of the utility. You can try setting the DNS manually and see what happens.
The other nagging possibility is that you picked up a chunk of malware trying to do a DNS hijack that may not have been entirely successful in installing itself but got far enough to bung things up. That eventuality would be better addressed to one of the malware forums, but for now lets check a couple these things out first.