There is an on-line contact form, http://www.avast.com/contact-form.php?loadStyles for: * Sales inquiries; Technical issues; Website issues; Report false virus alert in file; Report false virus alert on website; Undetected Malware; Press (Media), issues.

  • If you are reporting an FP, then you get another input field open, enter the web URL for the site you wish to submit for review (Network Shield), etc. A link to this topic also wouldn’t hurt, but since you have edited the information isn’t available.

You say it is for a couple of IPs, presumably these IP addresses host more than one domain ?
The network shield may have an IP block rather than a domain block if there are multiple domains on the IP that were infected.