Can not RENEW IP address...

Please forgive me to to put this thread on "Internet Related Issues" section too. I have already tried in "Laptop and PDA" section but no answer.

My laptop just recently started to give me this problem of not being able to connect to internet from time to time.
Often I try to flushdns from command prompt and it connects OK for a while but later on gives me the same problem again. When I try to repair "local area connection" often it can not RENEW IP address.
I connect to Internet via Zyxel Prestige 600 by cable ADSL.
I have AVG7 Free version, Spybot, Spyware Blaster, Windows Defender and Ad-Aware SE Personal. They all are up to date with clean bills. I also have ZA 6.1.744.001 free version. My XP firewall turned off.
Any help would be appreciated.

Continued here: http://discussions.virtualdr.com/sho...d.php?t=204085