NEW YORK (AP)--Research In Motion Ltd. is offering few details about two major outages in a week with its popular BlackBerry service, which delivers e-mail to wireless devices that many users affectionately call CrackBerries.

RIM, which makes the pioneering mobile devices and provides the e-mail service over cellular networks, attributed a June 17 outage lasting nearly four hours to a software upgrade "that did not operate consistent with prior testing."

The Canadian company said a second North American outage on Wednesday was the result of an unrelated "hardware failure." A RIM statement said a "back-up system functioned with lower capacity than expected and the lower capacity then caused latency in message delivery for some customers."

RIM declined to elaborate on the number of customers affected or the nature of the software and hardware involved in the two incidents. The company also seemed to dispute the magnitude and length of last week's disruption.

Cellular carriers Cingular Wireless and T-Mobile said on June 17 that service for all of their BlackBerry users--at least 1 million people, but probably many more--was down nationwide nearly four hours.

RIM, after failing to acknowledge that morning-time outage until hours afterward, initially described the disruption as "brief." This week, a company statement said "some customers were impacted longer, but the majority of customers saw service return within two hours."

Cingular and T-Mobile operate networks based on the same wireless technology. By contrast, there was no outage for BlackBerry users on the networks run by Sprint Corp. and Verizon Wireless, which use a different technology. Nextel Communications Inc., which reported scattered disruptions for its BlackBerry users, uses a third technology.

RIM, based in Waterloo, Ontario, operates data centers that steer e-mail between BlackBerry devices and companies' internal computer networks.

Service outages have been extremely rare for BlackBerry, and none in memory have been as severe and lengthy as last week's disruption.

RIM said Friday the two outages were not a sign that the growing popularity of the service might be straining its systems. The number of Blackberry users grew to 2.5 million by the end of March, up from about 1 million a year earlier.

At least 1 million of those users were affected by last week's outage: T-Mobile recently disclosed that about 500,000 of its customers are BlackBerry users, while Cingular has at least that many; that company bills itself as having the largest base of BlackBerry subscribers in the world.

Cingular is owned jointly by SBC Communications Inc. and BellSouth Corp. Verizon Wireless is owned in partnership by Verizon Communications Inc. and Britain's Vodafone Group PLC, and T-Mobile is a unit of Germany's Deutsche Telekom AG.

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