Problem with reverse / change sign on account

I had to zero out a few accounts and reload the balances to new accounts; I used Smartview to submit these changes.  I did this in the Dev environment.  One of the accounts was zeroed out in error.  I reloaded the balances to that account.  That particular account has the "change sign" checked in the data load mapping.  It worked correctly before I reloaded the balance but now the change sign is not functioning for that one account.  How can I get the account to calculate with the reverse sign now?