It is recognised that verbal texts do not result only from words. They may involve the mental manipulation of other modes of representation such as images and sounds. If this is the case, we must consider what is not operating with writers who find it extraordinarily difficult to produce verbal texts. Are they failing to mentally code or manipulate modes as they write? This paper reports on issues that arose when using extensive interviewing after text production by 10-year-olds, and finds that not only do some students not use other modes than words, but also that it is possible to help them by using multimedia as a modal scaffolding. Further, the study found that skilful verbal text producers might be hindered by multimedia, finding that for this group, working in a concrete manner with various semiotic modes can hinder text construction and that the students verbalised this as the multiple modes in the software disturbing the process of crossing between mental imagery and words.