AVG, Spybot S&D & AdAware not updating

I have a client running XP Pro SP3 that was infected with the Heur (Antivirus XP 2008) I cleaned & removed all traces of it, but for some reason I can’t get updates on any of the the programs mentioned above. I have full internet access & can download anything except thru those programs. The hosts file is fine, prefetch cleaned. Ran Ccleaner. The only other thing is that NIS 2007 is running. All scans from all programs come back clean, but still can’t update. Uninstalled & reinstalled AVG no change. Currently running an upgrade to NIS 2008 to see what happens. I did not try to update NIS 2007. Any suggestions??? I’m not sure if there’s a new virus out there or what.