Motherboard Overheating?

I have an ASUS M3N72-D motherboard with an Athlon II X2, 2GB of HyperX DDR2 1066, and a GeForce 210. It is pretty new, as I bought it about three months ago. I have never overclocked or fiddled with the BIOS, but recently I downloaded some temperature reading programs to moniter my hardware. The first time I checked my motherboard temperature, it was 65C. Now it hovers near 78C. I have never heard of a motherboard reaching this temperature before. Should I be worried and if so, should I RMA it?