CUA switched over to its new core banking system on the weekend and yesterday reported that the system was working; that it had been reconciled; and that all customer funds were accounted for.On Tuesday, a couple of news sites reported that customers were complaining about losing access to their accounts and that balances were going missing.The bank said no funds had been lost but that "some changes in the way our accounts operate and the timing of payments resulted in some customer concerns which have now been resolved."CUA's chief executive, Chris Whitehead, said some customers have had difficulty with the new security arrangements for online banking. CUA has introduced an extra security code for enabling payments to first-time payees, and a new log-on protocol."We have also changed the procedure for redrawing from loan accounts," Whitehead said."We wrote to all customers about these changes, but we will have to look at how we communicate."During the conversion period over the weekend, ATMs did not give balances. Some non-CUA ATMs showed a zero balance, which led some customers to worry that they had lost funds.Whitehead said calls to the call centre were up, but many of them were comments about the look and feel of the new service. "We don't want to trivialise that. We will have a look at it."There are no issues with the integrity of the system," he said.As a result of the increased number of calls, access to the call centre was taking up to 15 minutes. With the new system in place, CUA has plans to upgrade the functionality of its online banking service, speed up product development, and integrate various parts of the credit union