I asked a similar question a few months ago, but got no respons, so I think it's a bug.
Unfortunately, you'll have to redo the editing in Dreamweaver everytime you export.
If this is a bug, it's probably in the CssLayers.htt file.
You can find this in the Program Files/Adobe/Adobe Fireworks CS4/Configuration/HTML Code/ directory.
If anyone could resolve this, that would be very nice.
Are you getting a message from Fireworks that there are overlapping objects and it will creating the layout using Absolute Positioning?
For me, this is not the case. Could you test, centering a background image in a blank page? This isn't working for me.
Post a link to a file please.
Here are some files. The background-image I used, contains a printscreen of the HTML settings. This is in Dutch, so I'll explain some of it. I changed the repeat to no-repeat (dutch: niet herhalen) and the page-alignment to center/centre (dutch:centreren). In the CSS you'll see that both settings didn't export.
Could you test these? Thanks in advance.
P.S.: There is a maximum of 3 attachments, so I left out the html file. If you want it please let me know.