If your iPhone 3G's been acting a bit funky since you got it, there may be a good reason for it.

According to CNET, analyst Richard Windsor of Nomura published a research note over at GigaOm today singling out the iPhone's 3G Chipset, made by Infineon, as the probable culprit for reception problems reported by some users. These problems include dropped calls, service interruptions and abrupt networks switches experienced by iPhone 3G users.

Per Windsor's report, similar problems were experienced by cell phone users five years ago when 3G phones were first launched in Europe.

"We believe that these issues are typical of an immature chipset and radio protocol stack where we are almost certain that Infineon is the 3G supplier," Windsor wrote. "This is not surprising as the Infineon 3G chipset solution has never really been tested in the hands of users. Some people will not experience these problems as it is only in areas where the radio signal weakens that the immaturity of the stack really shows."

Should Windsor's theory prove correct, this would present a problem for Apple which a firmware update would be unlikely to solve. The problems may be confined to a certain build of iPhone 3G handsets or a certain batch of chips.

An Infineon spokesman declined to comment on anything iPhone-related, but said he would check into whether the particular chipset used in the iPhone 3G had been used in other phones. Apple has refused to acknowledge any issues with the iPhone 3G.

Stay tuned for additional details as they become available and let us know if you've experienced these problems in the comments or forums.