IIUC, you click on the text icon (tooltip say "Text Object");
you click and drag to create a textbox - at this stage all you have to do is start typing - the text will automatically go in the box, i.e. it has focus. If the focus is elsewhere, a double-click in the textbox will give do the job.
I'm on windows 8 here (for a change). I notice, when I created the textbox, there was a blinking cursor in it - but it was so small it would be easy to miss. Funny I just drew another textbox and I see a full-size blinking cursor... Do you see a blinking cursor?
Hope that helps!