Apple has been doing their best trying to find a fix for the battery issues that have been causing problems to some of their new iPhone 4S' users, and may be closing in on a fix. But, today there are reports that there is an audio bug when using wired headsets on the iPhone 4S which causes echo on calls. The reports have been documented on the Apple's support forums, and have been verified by a couple of sites, including BGR. The problem occurs when making a call and using the wired headsets, either from Apple or 3rd party headsets. There is an echo that occurs during a phone call at random ocassions. However, Apple has not yet commented on the issue and has not announced any official statement. Of course, there are work-arounds for this issue, and the easiest is to just not use a wired headset when making calls. If you really want to use a wired headset, you may temporarily fix the issue by unplugging the headset and plugging it back in when the echo occurs, or by turning on the speakerphone and turning it off.