Blackberry assured its users that services across Europe, the Middle East, Africa and India were ‘operating with significant improvement’ this morning, following a disastrous three day outage.

Users of Blackberry’s messaging and email services worldwide have been experiencing severe disruption since the 10 October, when a core switch failure within RIM’s infrastructure at its data centre in Slough, Berkshire in the UK caused the system to fall over.

Unfortunately for Blackberry, somebody was slightly trigger-happy with an announcement on Tuesday that the system was up and working again; compounding the frustration for vast numbers of users when it promptly fell over again. Late on Wednesday reports that users in the United States, Japan and Singapore were also having difficulties began to surface.

“Although the system is designed to fall over to a back-up switch, the fall over did not function as previously tested,” said Blackberry following the second collapse. “As a result, a large backlog of data was generated and we are now working to clear that backlog and restore normal service as quickly as possible.”

With the significant improvement of services this morning, though far from a perfect service far all, Blackberry blamed ongoing disruption on a system backlog.

Customers have been venting their frustration at the Canada-based Blackberry owner RIM, with many turning to Twitter to express their annoyance. “Dear Blackberry, I think it’s nice that you’re honouring Steve Jobs’ death with a 3 day silence,” tweeted one disgruntled user.

“By far the worst part of this Blackberry outage is that I have to admit I have a Blackberry,” said another. Meanwhile one bar in the Netherlands even began offering owners of broken Blackberry devices a free beer to help cheer them up.

However, joking aside, those at the top of RIM will be well aware that for businesses dependant on the Blackberry email service; this prolonged outage will constitute more than a minor inconvenience.

Confidence in the Blackberry brand will have been severely damaged by this episode; by the lack of detailed and timely customer communication; and by the sheer scale and longevity of the outage.

And with RIM already facing increasing calls for compensation, this folly has come at a terrible time; what with the launch of the iPhone 4S, a host of advanced new Android devices hitting the market; and with many businesses already considering a move to its rivals, RIM has some serious work to do to restore confidence.