also might have had a massive hatching out. did you look closely at the empty cells to see if there were eggs in there again? in a new hive, the queen will lay a lot of eggs all at once and they will pretty hatch out all at once...with in a day or so of each other. the queen will go back and refill those cells. you can have what looks like a poor brood pattern, but if you look very closely, you'll see that the cells are refilled.
if you find that she is not refilling, then you have a problem.
did you check closely around that brood and on other frames to make sure she is continually laying. you may have very small larvae or eggs elsewhere that you missed.