If the balances are different there are a couple of places you can check to see what the differences could be:
Take a look in the Nominal Enquiries and look at the client bank nominal for the period your Bank reconciliation is for.
Put the transactions into transaction date order by clicking on the header at the top of the page. Check all transactions in that period are dated the period dates.
Check that there aren't any items in the next period that are backdated but have been reconciled in your Bank reconciliation.