Research In Motion (RIM) has discovered the reason for its BlackBerry failure Tuesday/Wednesday. The company says it was the result of an insufficiently tested software upgrade.

Users of the service across North America suffered outages with many emails failing or delayed beyond the system getting back up-and-running. In a statement BlackBerry said the failure was trigged by "the introduction of a new, non-critical system routine" designed to increase the system's email holding space.

The company fully admitted the problem that "the pre-testing of the system routine proved to be insufficient". RIM also experienced a bad performance from the back up service designed to keep operations going in result of a failure.

BlackBerry is now working on the problems it came across in order to prevent it happening again. The company has over 8 million customers across the globe. It is estimated that RIM has around 45% of the market for smartphones.