Iphone 5 and Ihome clock

I recently bought my first iHome product, an iPL10. I do not like how SMS tones are amplified thru the clock's speakers while I have it docked and charging. There is a power button to turn off the sound, but it always turns itself back on when a tone comes thru. Is something wrong with my clock or is this the usual? Seems useless to have a toggle if its just going to be on all the time regardless