i decided to partially join 21st century yesterday and had at&t liven up text messaging for my q10. when a draft text message exceeded two lines, i found the screen would not scroll and i would be typing blind unless i got off the keyboard and manually scrolled the screen down. i googled and found the workaround for now (must use 9point font or smaller) (sigh, sort of like earlier issue with displayed text on locked screen, for which i had to go down to 12point before). hope blackberry can fix this problem too
Q10 Text Message Box Does Not Scroll Past Two Line... - BlackBerry Support Community Forums