The balances ("Total sum:") of accounts and sub-accounts are not calculated properly. It appears as though transactions are still properly registered as debit/credit in transaction list (they have the appropriate color for their type), but the sum does not appear to make the distinction in all cases (it may consider all transactions to be credits or all debits).
This affects the current version on the Android play store as of 2014-05-26, namely 1.3.2.