Is Apple iMac production suffering a slowdown?

This morning, I started getting notes from people saying that Apple (AAPL) had notified them of delays in shipping their newly purchased 27-inch iMacs. I chatted with an Apple rep online who told me that indeed there had been delays for shipments of the 27-inch quad-core models. However, the people who told me of the delays had purchased both quad- and dual-core models. This seems to imply some sort of last-minute manufacturing glitch for Apple.

The company is known to run an extremely tight inventory ship with Chief Operating Office Tim Cook being among the highest-regarded logistics and operational executives in consumer electronics. Apple keeps very low levels of inventory on hand and is an avid practitioner of just-in-time manufacturing methods. Apple also outsources most of its production to fabrication facilities in China. Its biggest partner there is Foxconn, a subsidiary of Hong Kong electronics manufacturing HonHai Precision (HNHPF).