Edited: SPDIF Problems (after installing a software program) - Need Help

I recently installed a program called iReal Pro to my Mac. It is like Band in a Box where it plays an automatic backing track for you. At first, no sound could be heard. I contacted them and they sent me a different version. Then, everything seemed to work. However, know I am having this problem:

* After playing for a few minutes, I hear a loud "pop" and
* Left and right volumes go to zero
* Panning is Centered on both channels
* and are panned to the center.

It is as though a MIDI type command is being sent via SPDIF every few minutes telling my iMac to do this. I deleted their program and it still does this. I'm not sure who/what is the culprit here: the KPA, the MOTU 828mk ii, the iMac with the latest OSX or what. Does anyone have any advice? I am working with the software folks on this. There was something mentioned about "sandboxing", does anyone know what that means?

Thanks in advance if you can help.

Problem solved. I searched the internet and found that I could do a "Reset" of the MOTU 828mkii by disconnecting the firewire cable, pressing Setup, then Select, then Value. It reset it to the factory defaults. Now, no more pops and no more shutting down SPDIF every minute or so. Somehow it got corrupted. It may or may not have anything to do with the software I installed. Noting here for my future searches or if anyone else has an older MOTUI product.