Its possible that it is a number of things. Run the design checker under
tools and see if that catches any problems. However I suspect this is
because this has been a problem sometimes with Pub 2003 and wide screen
laptops. Sounds like it is still an issue for Pub 2007. There hasn't been an
answer that works for everyone.

You can try adjusting your screen properties. Right click your desktop >
properties > Settings tab > Advanced. Change your DPI setting to 96 dpi.
Delete your IE cache and view your site again.

If that doesn't fix it, log on to your webhost, and delete your index.htm
file and the index_files folder. Don't delete any other files or folders if
they exist in the root directory! Open your Publisher web publication >
Tools > Options > Web tab. Uncheck "Rely on VML..." and "Allow PNG...".
Publish to the Web, and upload your new html files to your web host.

After deleting your IE cache, view your site again.

If that doesn't work, then change the screen resolution under the Settings
Tab to the same setting as on your desktop screen. Then republish new html
files as you did before.

And if that still didn't help, you can produce your html output on your
desktop, instead of your laptop.

Which version of IE are your using? I am hopeful that IE 7 will fix a number
of issues with Publisher.

DavidF