IOS 5.1 doesn't solve the call-problem ??from your iPhone
If you have an iPhone 4S then it is likely that at least once to be having problems with calls made ??from your device. I still have problems with sound during calls but for some problems related to closing a call or initiate sound a few minutes after starting it.
Although Apple said it would solve all problems by launching iOS 5.0.1/5.1 to the users, here in reality things are completely different now. It seems that iOS 5.1 will not solve problems by closing the sound, at least this says the device owners who discuss about iPhone 4S on Apple forum.
Some users of the Apple Forum say the same problems were encountered on the iPhone 3GS/4 so it would have as the main culprit the iOS and not the terminal iPhone 4S. Although iOS 5.1 now seems to have solved the problems, this version of the operating system is not yet publicly available on iTunes so Apple still has time to fix what is broken. It is very possible that this week or next week to have iOS 5.1 beta 3 available for developers or even possible to have iOS 5.1.