This happens in ClarisImpact 1.0 and Claris Works 2.0 (including localized versions). It is fixed in ClarisWorks 2.1
If you use the Check List Outline Format to keep track of things completed you need to be sure to save your document.
To see the error: if you open a previously created ClarisWorks 2.0 or ClarisImpact 1.0 Word Processing document using the Check List Outline Format, put a check in one of the boxes to indicate that an item has been done/completed, then close the document, you will not be prompted to save changes. Upon reopening the document, you will find that the check box is no longer checked.
To work around the problem, do some sort of text editing in the document or select Save from the File menu before closing.