When your mail system notifies you with a "beep" that mail arrives, HyperCard intercepts this signal and causes the Macintosh to emit a constant beep, that seemingly cannot be stopped unless you restart the computer. If you find yourself affected by this, remove the MS Mail desk accessory. As soon as the Mail window opens, the beep sound will stop. This does not occur in HyperCard 2.0
This article is adapted from the Claris Tech Info database.