Motorola(MOT), which originally discovered the problem, said the performance issue only affected a "minority" of network configurations and that fewer than three thousand of an unspecified total number of customers are affected by the problem.
As a result of the delay, Motorola said today that it is postponing shipment of its ModemSurfr and VoiceSurfr 56-kbps modems and that customers who had already bought modems can have the units replaced at no cost.
Rockwell emphasized that the problems were not due to manufacturing defects and noted that the central site modem chipsets used by online service providers were not affected. The company still expects to deliver its software upgradeable central site modem chipsets before the end of March.
The performance issue is likely to affect other modem makers using Rockwell's K56flex technology. Other companies may choose to offer a software fix for the problem rather than replacing entire modems, a spokesperson said.