It seems that there was a printer error. If you are using an RDP purchased in 2002 then you should read this article to see if you need a replacement.
PADI recently issued a recall notice for certain Recreational Dive Planners (RDP). Errors by the printer caused inaccurate or missing numbers on these RDPs.
While analysis of the problems shows that the risk of injury from errors is remote, for the sake of safety, we ask that you immediately check any RDP that you purchased or received during this period, against the product and production codes listed below. Please note not all RDPs shipped during the latter half of 2002 have printer errors ...