Shared variable returning previous value when it should be zero

[annadswede]

Using Crystal 8.5 to report on two compare inventory pounds from two different datasources. Using subreport to summarize total pounds of an inventory item from one datasource. Declaring a shared variable in subreport in order to calculate the difference between the inventory for each item (subreport lbs. minus mainreport pounds). Variable reports accurately in main report as long as the subreport item "does not exist" because no inventory exists in this database. The variable in this case is printed exactly as the previous record. This continues until an item is encountered that exists with pounds in subreport.
Any ideas on how to supress printing the previous record when a "blank record" is encountered.

Any help is appreciated. Thanks,

Annadswede