@ msroth
I believe bob3160 uses magic jack with avast and no problems, he isn't on-line right now. Hopefully he will see the topic's subject and give some feedback.
There is little point in uploading it as a false positive (FP) unless avast is actually alerting on one of its files, which you haven't mentioned.
You could try this in the meantime and see if that resolves the problem:
AvastUI > Security > Antivirus > Web Shield > Settings and check the 'Scan traffic from well known browser processes only' option, see image, click to expand.