ClarisWorks version 2.1v2 has a known issue when formatting an object with the Text Wrap option. If the object is located at the right margin of the document, the text which is actually effected by the text wrap option will revert to single line spacing.
If you paste the graphic inline or move it to the left margin, it will work fine.
This issue is fixed in 2.1v3 and 3.0.