Why Avast marks our files as files infected with a virus?
Win32:Evo-gen [[b]Susp[/b]] = suspicious
You can report it using one of these options
You can upload files and report issues to avast here : http://www.avast.com/contact-form.php (select subject according to Your case)
You can use mail
send to virus@avast.com in a password protected zip file
mail subject: False Positive / undetected sample (select subject according to your case)
zip password: infected
or you can send files from avast chest. http://www.avast.com/en-eu/faq.php?article=AVKB21