This might be a compatibility issue on the Theta processor when doing certain bluray audio formats. You could try discs that have different audio formats:
DTS-HD MA
Dolby TrueHD
Dolby Digital (compressed, usually on a DVD)
DTS (compress, usually on a DVD)
Then contact Theta.
DTS-HD MA
Dolby TrueHD
Dolby Digital (compressed, usually on a DVD)
DTS (compress, usually on a DVD)
Then contact Theta.