Internal keyboard comes up missing when trying to respond to text

[DonCarlos]

wondering if anyone else has experienced this mystery. Sometimes when I am about to respond to a text, the keyboard is gone. Normally when I touch the window next to the photo icon a keyboard will be displayed. but sveral times now, nada. What I have done to get it back is to shut down and reboot. But I am wondering if this is just something that is wrong with my ios or phone. I have a iPhone4, just got it 6 weeks ago. This had happened about 5-6 times. Perhaps I am touching something to cause this. Hmmm Any comments are appreciated.