The page on my site does mention that the methods have not been tested for RoboHelp 8 and above. It occurs to me that you may have tried the method using a table added by using Insert > Table. Try with a table added using the Insert Table icon. That inserts tables in the same way as RoboHelp 7 and below.
Post back if that still fails. Also add which of the two methods on my site that you are using.
See www.grainge.org for RoboHelp and Authoring tips
Not yet -- will let you know when I get a chance to try it
Michael West | Business Improvement | Aurecon
Ph: +61 3 8683 1996
PO Box 321, South Melbourne | VIC 3205 | Australia