To know if a file is a false positive, please submit it to JOTTI or VirusTotal and let us know the result. If it is indeed a false positive, send it in a password protected zip to virus@avast.com
Please, mention in the body of the message why you think it is a false positive and the password used.
No need to recall the mail. The Alwil team will have a look at it and if it is indeed a FP, they will correct it as soon as possible. But submit the file to Jotti and see what is says.
Jotti uses the Linux version of avast and as such some unpackers aren’t included, which is probably it isn’t detected. So the better multi engine scanner would be virustotal, not to mention that it has 27 different scanners.