There is a constant battle with autoit scripts and avast, mainly because it is written using VBS I believe and many malware writers use to write malware.
If you are getting a virus warning that you believe is a false positive, then if you can zip and password protect ('virus', will do) the suspect file and send it to virus @ avast.com (no spaces), or send from the chest (after adding it to the User Files section of the chest).
Give a brief outline of the problem (possibly a link to this thread), the fact that you believe it to be a false positive and include the password in the body of the email. Some info on the avast version and VPS number (see about avast {right click avast icon}) will also help.
I don't know if this is a workable option but you could create a folder for your scripts and exclude that from the avast scans.
Standard Shield, Customize, Advanced, Add and
Program Settings, ExclusionsYou could also check the offending/suspect file at:
VirusTotal - Multi engine on-line virus scanner I feel virustotal is the better option as it uses the windows version of avast (more packers supported) and there are currently 30 different scanners.
Or
Jotti - Multi engine on-line virus scanner if any other scanners here detect them it is less likely to be a false positive.
Whichever scanner you use, you can't do this with the file in the chest, you will need to move it out.