Hi scryer21,
As long as the data have been posted successfully in Ledger (please check this out), the Financial Reporter will be able to output the correct amount. The problem you are probably running into is the formula syntax in the cell used for calculating this interest amount is not correct.
Make sure that the correct account(s) is used in the formula. If you are unsure of what that syntax should be, compare against other formulas in your spreadsheet to get an idea how it works. You can also post here what you are trying to do (ie a sum of accounts from A to B, for department X only, or something similar).
Our newest release of Adagio Ledger 6.8B has updated the Financial Reporter extensively, adding new features and making it easier to use. If you are not using Ledger 6.8B, please also indicate which version you have installed.
Regards,