Mixdown problem

Mixdown beeping problem

If anyone can help me I am having trouble mixing down a song I recorded. I recorded a two track song and then mixed down the two tracks to create one master track so I can burn it to a cd. But however, when I did this there is some strange 3 tone beeping that appears randomly throughout the song. I’m wondering what it is that I need to do to fix this problem. I am using the unregistered version of N-Track so I don’t know if maybe this is just something N-Track does in order to get people to but their software instead of using it for free, or maybe I just screwed up somewhere in the creation process. Any help would be greatly appreciated.

It’s just what you suspect - an organ sound every 30 seconds or so as a way to get folks to buy the product.

I figured so. Thank you very much for helping me out.