2.0 Set-up problem (Loud Popping Noise)

[gotexas872]

I was playing my new setup the other day and my receiver shut-off after playing music for 15 minutes at -2 dB. I let the receiver cool down for 30 minutes and gave it another run. After five minutes of watching over the air t.v. at a volume of -35 dB I heard a loud popping noise come from the speakers. I immediately turned the receiver off and waited a day to turn on my receiver again. The next day, before playing any audio, I made some changes in the receiver settings and watched t.v. for 2 hours then a movies for 2 hours at -25dB and did not have the popping noise problem again.

My question is if my receiver settings and/or not letting my receiver cool long enough could have been the culprit of either 1) my receiver overheating or 2) the loud popping noise? These are the settings I changed the following day:

Amp Assign - From: Front B To: Normal

Volume Limit - From: -20dB To:-10dB

Floor Left Volume - From: 1dB To: 0dB

I have a pair of Acoustech PL-76 floor-standing speakers connected to a Denon 1611 receiver. Here are the specs for the speakers and receiver:

Acoustech PL-76 Specs

Design: Video-shielded 200-watt (500-watt peak) 2-way horn tower with dual 6 1/2" woofers.
Frequency Response: 30Hz- 23kHz
Sensitivity: 96dB @ 1 watt, 1 meter
Recommended Power: 10-200 watts per channel RMS, 500 watts peak power
Impedance: 8 ohms

Denon 1611/591

Surround System Class 7.1 channel
Amplifier Output Details 75.0 Watt - 8.0 Ohm - 20 - 20000 Hz - THD 0.7 % - 5.0 channel(s) ( Surround ),
120.0 Watt - 6.0 Ohm - THD 0.08 % - 5.0 channel(s) ( Surround )

I have also asked about my problem on AVS Forum but I would be thankful for any feedback here as well.