Now for Quantive: you must add this to your template.css:
div.rt-footer-bottom-wrap {position: relative;bottom: 0;height: 0px;width: 100%;}
and in templateDetails add at the end of the code but before </params></install>
<param name="experiment" type="gspacer" default="" description="" label=" " glabel="EXPERIMENTAL" />
<param name="dyngrid" default="60" type="text" class="text-short" label="DYNGRID"/>
and in the "features" folder of the template replace the styledeclaration.php with the one attached.
As always be sure to clear all kinds of caches and more important: keep a backup of your files
Djamil was so nice to pick up and improve my idea, so the credit for the code goes to Mr. Legato.
I had just to add a single value to make it work.
After you added this you should be able to change the width of the Quantive template via template settings.