Just thought I would share my problem. In the hopes that it may help someone else. I recently updated my Onkyo tx-nr609 firmware to the latest version released 3/28/12. well after updating everything worked fine except the THX sound fields. the receiver would click and the speakers would pop and stutter only on the thx modes. the sound became very distorted (only on thx) at all volumes and at higher volume the receiver would recognize the distortion and turn off. Needless to say I contacted Onkyo and now my receiver is being sent out to Best Buy service center. Onkyo's first response was...it must be your speakers causing the distortion and auto protect mode. the second response from a different phone rep. was one of your circuits must have went bad and its not compatible with the new firmware. Well long story short I just wanted to share my experience and possibly help someone else before they update to the new firmware and are down for 2-4 weeks for service. I should know what the true problem is in a couple of weeks. Its just so darn coincidental that the THX modes failed after the firmware update and everything was A-Okay previously.