Problem with Goodsync said to be due to Avast

I have had a problem with Goodsync which started after I last updated it. Goodsync support said

this problem was caused by bugs in AVAST.
GoodSync creates Windows Task that starts it after install, in GUI mode.
AVAST would run this task multiple times, even though it must be run only a single time, due to bugs in AVAST, which we suggest you should report to them.