No. I've had it since new. But never really played around with it with my old speakers.
@Mark E. Long : the amp assignment was definitely one of the issues. It was set to 'Basic' (whatever that means). So I turned it to 9 channel. Boom. The rear speakers now work for stereo.
I also turned up the dB to various levels on all of the speakers. Then I turned on the Dolby sound modes. At first I thought it was 'fixed' (it definitely sounded better), then my daughter walked into the HT room and (without me even saying anything to her) asked me why it sounded so (her exact word) "muffled". So I turned it to 9 channel stereo, and she looked at me and said "way better".
I'll try playing around with the EQ at some point, and when the YPAO microphone arrives next week I'll run that and see, but for now I have full surround sound using the 9 channel stereo mode and it sounds awesome.
Thanks for all the help troubleshooting guys. Muchly appreciated.
Cheers,
}Fear_Inoculum{