I have been creating a website for a university project with Xara Xtreme 5. I have encountered a problem on each page when entering text. There appears to be a rectangle box near the centre of the page where no text can be entered. Through all my efforts I have not been able to identify any box that could cause the problem, as far as I can see there is nothing there. The problem occurs both when writing in a text box and when copying text in RTF from word.

Any ideas on what the problem could be?