Just tried it, and that didn't seem to have any effect. It's not just a tiny bit of overlap though: it's the #tertiary being right on top of #primary; I wonder if that indicates a different bug?

Uploaded a screenshot: http://bugs.dwscoalition.org/attachment.cgi?id=1882

Here's the code I used by the way:

#primary, #secondary, #tertiary, body, #canvas {
margin: 0;
padding: 0;
}


Hm, the three-columns-right appears to be affected by the same bug as the two-columns-right, as well, where the modules in #tertiary end up in the middle of the content (but I guess that'll be fixed by the same thing)

(I am wickedly tempted to hide the three-columns-right option until something is worked out, tbh :-))