How do I get Frame to acknowledge the colwidth value in the <,colspec> element.

How do I get Frame to acknowledge the colwidth value in the <,colspec> element of a CALS table when opening a Dita file. I have already commented out "writer use proportional widths" in the R/W rules. This preserves the values when saving but on Open the column widths are changed. This really throws a wrench in round tripping Dita files. We end up spending days copy-fitting tables after a book build. I used DitaFMX for a while to solve the problem. But that comes with other baggage like no support for DIta 1.3.

- Guenther