1. The most important point is that a dreamweaver layout table adds a pixel at the top of the table. For sample code of a dreamweaver layout table, click here. You might as well not fight this, since dw will put it back in if you need to modify the imagery at the fireworks level.

This means that if your background image is at the top, for example, you are going to need to "push it down" by one pixel to make things work.
2. A great way to include a background image that repeats across the top only ONCE is using the following code in the HEAD tag of your page:

<style type="text/css">
3. <!--
4. body { background-color: #FFFFFF; background-image: url(images/home_pgbg_v03.gif); background-repeat: repeat-x}
5. -->
6. </style>

Where home_pgbg_v03.gif is your background image.

This brings up the next quirk of dreamweaver; if this page is a template, dreamweaver will not match up the relative link correctly because it doesn't know what to do with a tag that says url(somefile.gif). When you use the template to create a page you're going to get the following translation: url(templates/somefile.gif. You have little choice but to do a sitewide replace every time you modify the template, unless anyone has any better ideas.

One final point is how to slice at the top of the page. For my example page notice that I have tan, light orange, and black color bands, but the top layer is sliced exactly between the light orange and the black. That way the underlying black line in the background image (home_pgbg_v03.gif) will be solid all the way across.

One more thought which will be obvious; in this case the black line is actually on the second row of the table, so any images with white or other colors will cut off some of the black line.