Propane Smell

[jjackflash]

We took the Monty out for a few days than one night I started to smell propane,but no alarms were set off.I open all windows and turned on all fans than went out to check the tanks. I check the fittings and no leaks than realized I had the main tank on the drivers side turned off and the passenger side tank turned on. I turn the main tank back on and the smell has seem to disappeared. Would this have caused the propane smell? The smell was mostly in the bedroom.
Jack