Fan Stuck On.

Question

When I run the Microwave the fan stays running after it is done cooking. When I hit the vent/fan button the fan slows down a little for high then goes back to high when it is on low or off. The only way to stop the fan it is to unplug the unit but the next time you use it it stays on again after it is done.Also, I just tried it, when it is off and I hit the Vent Fan button it stays after I hit off. This is a new unit. It has a manufacturing date of Oct 7th 2007. I am not sure what the GE warranty is.