Apple is investigating reports that the latest iPhone operating system causes problems for users of the iPhone 3G, after a series of complaints on Apple support forums and technology blogs. Apple is aware of the reports and is looking into the matter, a spokeswoman told Digits.

Reports of the problems have been overshadowed by "Antennagate" -- complaints about the iPhone 4 antenna that led Apple to issue free cases to all buyers. But since the iOS 4 software became available in late June, user concerns have ...