Existing AR Memo Lines do not appear in the list of values when defining the revenue contingency ass

Hi

When defining assignment rule for parameter Memo Lines (Navigation>Revenue Management Super User>Revenue Contingencies>Assignment Rules>Create Rules), the standard ar memo lines defined in Receivables>setup>Transactions>Memo Lines> do not appear on the list of values, the LOV is blank, the seeded and additional memo lines defined do not appear on the lov. Please assist.

Thanks .Tumi