A photodetector circuit is being used to generate a pulse each time a customer walks into a certain establishment. The pulses are fed to an eight-bit counter. The counter is used to count these pulses as a means for determining how many customers have entered the store. After closing the store, the proprietor checks the counter and finds that it shows a count of 00001001₂ = 9₁₀. He knows that this is incorrect because there were many more than nine people in his store. Assuming that the counter circuit is working properly, what could be the reason for the discrepancy?