We are having the very same experience. We signed our software with a code signing cert from a reputable issuer (DigiCert). We discovered that Norton 360 was automatically quarantining the downloaded installer and most users had no idea how retrieve it from quarantine. We got whitelisted and then released a bug-fix update and voila the our app started getting quarantined again. We are losing potential users and it have been damaging to our company!
