Just finished cleaning up my planer again. I have noticed that there are 3 bumps running the full width in the main table of the planer where exactly below the infeed/outfeed rollers and the blade. It is obvious that the rollers and blade have pushed down on the wood as these locations and have subsequently made small bumps into the table. Is this normal? A book I have on planers indicate that there should be minimal gaps with respect to the flatness of the table.