A massive service outage of BlackBerry e-mail devices earlier this week resulted from a new storage feature that was not sufficiently tested, device maker Research In Motion said.
RIM said it was able to rule out concerns that the failure was caused by a security breach into its system or an inability to provide enough capacity to nearly eight million subscribers, according to a statement.
RIM also found that the outage was not caused by any flaws in its hardware or its main software infrastructure.
The company had introduced new software designed to make the use of temporary storage on the BlackBerry device more efficient.
But the procedure caused an unexpected problem that "triggered a compounding series of interaction errors between the system's operational database and cache," the company said.
The crash left politicians, lawyers, business executives and other "CrackBerry" addicts without wireless e-mail service on Tuesday night and into Wednesday morning.
RIM also defended the way it had handled the crisis, despite criticism that it was slow to communicate with subscribers about the extent and cause of the outage.
"RIM's first priority during any service interruption is always to restore service and then establish, monitor and maintain stability," the company said.
"Proper analysis can take several days or longer," it added, "and RIM's commitment is to provide the most accurate and complete information possible in such situations."