Numerous online reports this week have noted poor connections around the world for the popular iPhone 3G, but the finger of blame is now being pointed at chip supplier Infineon. A Reuters report yesterday cites a Nomura research note and a BusinessWeek article, both of which claim the German silicon vendor is at fault for dropped calls and unpredictable Internet links. The new iPhone 3G runs over HSPA networks – rather than the EDGE networks used by the first-generation device launched last year – and sold 1 million units in its first weekend of sale last month. Infineon has not confirmed it is the chip supplier for the iPhone 3G, but Reuters notes that Apple tends to restrict its suppliers from talking about their relationships.

Despite these reported problems, a Piper Jaffray analyst this week forecast that Apple will ship 4.47 million iPhones in its current fiscal fourth-quarter (ending September 27), around four times as many as it did in the year-earlier period. A separate study this week by Synergy Research Group (SRG) also found that Apple managed to remain the second-largest US smartphone manufacturer in the second-quarter of the year, despite a slowdown in sales as people waited for the arrival of iPhone 3G. According to the study, Apple trailed market-leader Research In Motion – manufacturer of the BlackBerry – but was ahead of Motorola, which leads the overall US handset market.