Wow... I hate seeing "unanswered" forums for such easy answers. I had the same problem. It's an easy fix but it took me a few minutes to find.
Go to the Preferences and choose Audio (not Audio Hardware). There is a check box for "Mute input during timeline recording. Make sure that is checked.
This really depends on how you monitor your audio. If you are directly monitoring your input, then you'll hear an echo. If you are not directly monitoring your input, you wouldn't. The echo isn't being recorded, it is just in how the audio is being monitored.
Now, even though this was an old post, at least there is an answer indicated.
Mark