Oops, we did it again!Barclays.co.uk, one of the biggest UK online banks, has been hit by serious technical problems resulting in its site being down for the last two days. A Barclays spokeswoman admitted the bank has been affected by two separate IT problems, preventing access to the site for most users. She said there were no security implications from the breakdown. Barclays users have complained of not being able to access the site for the last two days. A message on the Barclays Online telephone helpline this morning warned all callers of the problems, and encouraged them not to bombard the call centre with complaints. It said: "Barclays Online is currently experiencing systems problems which may lead to some customers having difficulty accessing the service. If this is the reason for your call, please try to log on again later." A Barclays spokeswoman admitted only that the service was down between 09:00(BST) and 16:00(BST) yesterday, and was experiencing limited problems again today. She said: "Every large online service provider has these problems from time-to-time. They are just business-as-usual type problems, but yesterday very unfortunately the problem took much longer to solve than expected, and we apologise for that." A source close to the situation said a "major incident management team" has been set up to investigate the failures. Yesterday's downtime was caused by an error in the log-on application which stopped legitimate users being able to access their accounts. In a separate problem today users received "timed-out" messages because of an unspecified hardware problem. The Barclays spokeswoman claimed this second problem was solved by 11.00(BST) this morning, but said the fixes may take a couple of hours to work through the system until the site was back to full functionality. This is not the first time the Barclays site has been hit by problems. In August last year Barclays left user details exposed on the site after a faulty systems upgrade to its Oracle-based iBank suite. It also allowed users to utilise the "back" button on a browser to re-enter live accounts - making the system liable to abuse.