Daniel,
Make them soft carriage returns (shift-enter) instead and a real paragraph marker is at the end. That way the widow/orphan stuff will keep it all together. It helps if you turn on the display of items like Paragraph Marks etc.
>Each line of text - 'Sincerely,', 'James', 'Teelphone number' - is a paragraph by itself because of the hard carraige returns. You usually keep paragraphs together on the same page by checking the Keep with next option of all but the last paragraph but it doesn't always work when pictures are involved. The error rate is very small but still unacceptable to my client.