Production delays may have cost Apple a million or more iPhone5 sales at the weekend, according to reports.
At the heart of the problem: the new iPhone5 display that combines the display and touchscreen, creating "in-cell touch sensing," Apple suppliers were said to be having difficulties constructing the new screens.
Sharp was reportedly unable to begin shipping the screens before the phone launch . Apple's other suppliers, LG and Japan Display, are said to be finding it hard to keep up.
"Apple is facing significant production constraints due to a move toward in-cell display technology," Barclays analyst Ben Reitzes wrote. "Apple is struggling to keep up with demand."
Pre-orders began at midnight on Sept. 14, but within an hour delivery dates were pushed back from the launch date of Sept. 21.
Apple announced that it had sold a record 2 million phones in the first 24 hours , but some won't be delivered until October.
Sales that first weekend were still a record with 5 million phones snapped up in the first three days - but many thought the company would sell at least 6 million devices in the opening weekend.
"We believe this shortfall is largely due to supply availability and the fact that most consumers are opting for the pre-order option," according to Topeka Capital analyst Brian White.
Apple CEO Tim Cook asked for patience from customers in Monday's news release announcing record sales.
"Demand for iPhone 5 has been incredible and we are working hard to get an iPhone 5 into the hands of every customer who wants one as quickly as possible," Cook said. "We appreciate everyone's patience."