This has been driving me crazy not only with the S4 but before this i had a Thunderbolt and the exact same thing happened. It happens when in landscape. I will type and send my message and when i hit the back arrow to move the keyboard away, its at the top of the thread. I then have to back out to where i see all my texts from everyone, then go back in to the one i was on to be back to the last text sent. Happens about 75% of the time. So then i usually download GoSMS or some other texting app but they all suck in their own special way. Is there something i can change in the settings or remove something....SOMETHING??