One way of controlling your tables is to use the layout tools to draw your table and cells. This tends to create a locked layout, but you need a very firm idea of what you want out of your layout before proceeding.
Part of your problem may be if you have merged a series of cells into one row. Cell merging is one area where Dreamweaver often introduces some serious errors.
You could create some transparent gif images and use them as cell spacers to prevent the table from rearranging itself. There are ways of getting Dreamweaver to do this for you - check out the help files.
One comment on the page you are woking on. You might want to change the word "cheap" to "inexpensive" or "cost effective". Cheap is one of those words that can be taken in a variety of ways but most often it is taken to mean exactly what it says, which is probably not the image you want for the site.
Try and post a snapshot of the page code and highlight your problem area. Dreamweaver sometimes mangles layouts and you need to know it inside and out to cover all the bases. I can only generalise here until I see the actual page code.