Either way the account should balance. It sounds like you have a problem in the database - have you Validated and Super Validated your file?
Can you get your last AMEX statement out Carljh & check closing balance on the last statement matches the opening balance of the current statement?
If they are the same check the opening balance of the last sttaement agrees to your account balance at the same date. If it doesn't match go back to where it did match. You possibly accidentally deleted a prior transaction?