Research In Motion said late Thursday that a malfunctioning new feature caused the outage which affected millions of its subscribers Tuesday night into early Wednesday.

Users of the popular Blackberry first started having problems around 5pm ET on April 17, which lasted until about 4am ET the following day. During the outage, e-mail and web access was unreliable, although users were still able to place phone calls.

In a statement, RIM said enhancements to the temporary storage feature of BlackBerries were implemented without proper testing. When the application malfunctioned, it ended up taking the Blackberry service down with it.

The issue "triggered a compounding series of interaction errors between the system's operational database and cache," thus leaving millions without reliable service as other parts of the software began to fail.

RIM denied that the problem was caused by some type of hack or break-in, which some news sources had been reporting in the days following the outage. It also defending its handling of the crisis, saying its first priority was "to restore service and then establish, monitor and maintain stability."

Some had criticized RIM's handling of the outage, saying it did a poor job of communicating the problem to its customers. However, it said it wanted to properly analyze the problem "to provide the most accurate and complete information possible."