Commonwealth Bank is adamant that the problems with its online banking system, NetBank, have been resolved and the issue is now done and dusted.CBA does not want to comment any further. It would not elaborate on a statement released on Monday afternoon.But that statement has opened up a new line of inquiry for those concerned about the stability of the bank's IT systems and the robustness of its business continuity planning (BCP)."The high transaction issue was resolved on Tuesday morning and the data display issue which restricted the ability of some customers to view their transaction histories online using the regular display balance feature, was resolved Sunday afternoon," the bank said in its statement. "This problem related to a software issue and we had IBM work with us to resolve the matter."The statement did not provide any explanation of the reason behind the spike in traffic to NetBank. Also, there was no mention of the results of forensic analysis undertaken last week to determine the source of the traffic that shut the site down.CBA chief information officer Michael Harte last week stressed the importance of the forensic analysis but a spokesman said CBA would not be providing minute detail of the bank's internal IT systems.There is also no mention of any apparent "denial of service" attack that was one of several competing explanations for the degraded service last week (and which, anecdotally, persisted yesterday as well).One of the curious features of the episode is the range of explanations offered by Commonwealth Bank over the course of a week.The bank's communications with the media and customers have, over recent days, appeared inconsistent.Explanations shifted from the cause and implications of the surge in traffic (either, or both of, a DOS attack and an end of financial year spike in regular traffic) to the narrower irritant of the bank's difficulty is retrieving the transaction history for customers.The statement provided a window into the CBA's IT management, and admitted to the software problems that IBM was called in to fix.IBM was brought in last year along with HCL Technologies and Tata Consultancy Services to provide application services and replace EDS, which had done the job for 10 years.It is believed the bank was quick to facilitate a handover of responsibilities for monitoring systems and to ensure that upgrades and changes to software applications did not have unintended consequences.Sources have told Business Spectator that the level two support teams that EDS had in place at CBA have been "descoped" and this has led to a loss of technical expertise.Business Spectator understands there is some push back among middle managers in CBA's IT department towards the new outsourcing partners.Those concerns may be just the usual complaints from managers forced to share their expertise with outsiders. Or it could be a deeper problem that will have to be resolved as part of the normal teething problems associated with new outsourcing contracts.EDS had the advantage of working across the entire bank and having responsibility for all the application