AT&T Inc. said Wednesday that a software defect in its network is limiting data uploads from the phone in some areas.

AT&T and Alcatel-Lucent have jointly identified a software issue, triggered under certain conditions. The issue has impacted uplink performance for less than 2% of AT&T's customer base ? those using Laptop Connect and smartphone customers using 3G HSUPA-capable wireless devices in markets with Alcatel-Lucent equipment.

Alcatel-Lucent is developing a longer-term software fix in the coming weeks, but in the meantime AT&T has implemented an alternative that provides normal 3G uplink speeds and consistent performance for affected customers using HSUPA-capable devices.

Apple Inc.'s new iPhone 4 went on sale in the U.S. and a few other countries two weeks ago. Last week, Apple acknowledged that holding the phone in a certain way might reduce its wireless performance, and that all iPhones show the wrong signal strength in some situations.