Problem while writing messages


I am new on this forum and I have some difficulties to write my messages in the text field here... In fact, when the message becomes bigger than the initial area, the vertical rule appears but then it becomes very difficult to type something. Indeed, if I write something or want to go down with the keyboard then the rule goes up and I can't see the text anymore..

I am not sure to be clear.. I am the only one who has this problem ? (I am using IE at present)