I have a Yamaha HTR-5250 with 5.1 and DTS, along with varied DSP's. Last night it starting shutting off automatically while watching a DTS disk at moderate volume. Turning the unit back on revealed the message "Check SP wires" on the front panel, indicating to me that there is probably some safety circuit being tripped. I have checked all the speaker wires and connections seem good and tight and there are no positive/negative crossovers. All my speakers are 8 ohm and the selector switch on the back of the unit is set accordingly. Frankly I haven't touched my speaker wires in two years and they are routed out of sight and reach (away from the kiddies) so I feel pretty good about the connections. The unit shuts off much less often at low volumes. Has anyone ever heard of this or had this happen. Could it be a short or something internal to the receiver, or do speaker wires degrade? thanks for any help.