Originally Posted by OffPavement
What the OP described sounds a lot to me like the odor put off by a vent free propane heater.
You guys sure have made this thread interesting though!
Here's a confirming spin on Off Pavement: Every year when I first light off my zero vent fireplace/heater in the basement it puts off a horrible stench and sets off the smoke alarms for about 2-3 minutes, then things clear up. It smells like half burnt gas due poor combustion. I've had in happen in motorhomes, stored off sight when the oven pilot is left on. Once discovered and vents/doors are open it clears. Appears the pilot in these stoves is not the best combustion, exhaust gases left to collect you'll detect it! Great science lessons on unburned propane however.