The echo may be the result of Biscotti's high sensitivity microphone picking up the sounds coming out of your TV speakers, creating a feedback loop that can be very annoying. Biscotti has built-in echo cancelling, but the laws of physics can be pretty persistent.
Is your Biscotti installed at the center, above your TV, as shown in the setup guide? If it is installed correctly, try turning down the volume on your TV a little. If the echo goes away and you can still hear the other party, then you're back in business. If it's too quiet or the echo doesn't stop, make sure there aren't any other speakers pointing towards the TV.
If you still have problems, contact our support team and we'll be happy to help.