Since the launch of iOS 4, iPhone 3G and 3GS owners complaints are posted at Apple forum and other technology blogs that after getting upgrade to new iPhone OS devices have experienced a lot of glitches like those are getting slower, quick drain of battery life, overheat etc.
But according to Apple company, is just investigating the issue with iPhone 3G over iOS 4 as they totally denied that they did not receive any complaint for the same issue by iPhone 3GS owners.
According to L.A Times, Apple spokeswoman Natalie Harrison said:
“We’re not receiving any reports regarding it being an issue [...]