Thanks so much for all the responses, I was gone for a few days and just recently got around to getting back to this thread. Sirquack's description is exactly what I have been hearing. With the 4th of July coming up it has been reminding me of hearing fireworks off in the distance. It is strange, I will hear the noise and then may not hear it again for an hour, very random.
Anyway, I first tried leaving the EP500 off for a day, but that did not seem to do the trick. I then tried tried unplugging it for over 24 hours. It did not return right away, but about an hour or so after plugging it back in it started again. Looks like I will be giving Axiom a call and see if they have anymore trouble shooting ideas. At least I am dealing with one of the bests and have no concerns about dealing with customer service.
