Hi Dan,
This has been a problem with versions 6.0.x and below. It has been fixed in the newest version 6.1.x, due out soon. You can download and test a beta version in the Download portion of this website. The production version should be out in a matter of weeks.
With older versions you can play around with the widths depending on what content you have to try to get them to align. In the new version we move away from html widths in tables to solve the problem.