Thank you both for the response. I'm not sure why there are excessive tabs as I thought the TOC had automatically created itself. I have found a work around by expanding the font in TOC 1 by 0.5 point. It seemed that it didn't like short words. If the word is 6 characters or fewer it will fail visibly on the screen. If it's 7 characters it *may* fail when printing but look ok on the screen. If I replaced the letter 'L' with another letter (E or P) it would print ok. So I assumed it was a bug with heading sizes and expanded the font and hey presto, all good.