Oven stopped lighting. Replaced the spark ignitor then oven started working again. Less than a week later the oven will light, and relight through the baking cycle a couple times, but then won't light after the 3rd or 4th time during baking cycle. I can hear the spark ignitor and hear the gas come on and will try to light three times then shut off. After about 30 seconds, over will try to relight again, but same thing happens. 3 attempts to light then shuts down.