Hi,
Well, if currency rate is fluctuating, it is possible.
E.G. my example from Poland. In September within few days currency rate EUR/PLN has changed from 4.40 to 4.60. We have received e.g. 10 000 EUR from customer one day valuated in PLN as 44 000.
Few days later we have paid 9800 EUR to our supplier, but we valuated it as PLN 45 800. At the end of the day we owned 200 EUR, valuated as debt of 1800 PLN.
Currency revaluation process is dealing with such situations - valuates your closing position in foreign currencies at closing rate.
You must dig into transaction details to identify the reason of such balance. It is still possible that you have transaction accounted at extraordinarily high or low rate manually entered, which is ruining your accounting balance position. But it might be normal as well.