You can report a false positive here:
http://www.avast.com/contact-form.php?loadStylesCan you inform the file as being a false positive? (click on the bottom right of the virus warning message).
As a workaround, you can add these files to the
Files Shield exclusion list.
Left click the 'a' orange icon, click on the Real-Time Shields folder at left > File Shield > Expert Settings > Exclusions > Add.
You can use wildcards like * and ?. But be careful, you should 'exclude' that many files that let your system in danger.
You can also add it to the general exclusion list (on demand scannings). Left click the 'a' orange icon, click on Settings button > Exclusions > Add.