If you have problems with the text boxes not showing correctly when adding either questions or category's, you may need to edit the settings in the following file.

includes/javascript.php

Find the following around lines 105

theme_advanced_resize_horizontal : "false"

and replace with

theme_advanced_resize_horizontal : "true"

This will then enable you to resize the text input box to whatever size fits with your screen resolution, by having the handle on the bottom left hand side of the box. (see image above)

Alternatively you could turn the nuke_editor setting to 0 in your config.php file, which is a permanent solution.