Personally when it comes to my system security I trust very little, I have no doubt that the Treewalk site does state that is is a false positive, but would you take the word of someone who you don't know who also wrote the software. If (and this is purely hypothetical) it were you and you were asked if there was any malware with your software (any there was), what would you say?
You are right to check but never take anything at face value.
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).
Give a brief outline of the problem, 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.
You could also check the offending/suspect file at:
Jotti - Multi engine on-line virus scanner if any other scanners here detect them it is less likely to be a false positive. You can't do this with the file in the chest, you will need to move it out.
Or
VirusTotal - Multi engine on-line virus scanner
