There are several possible reasons you’re having problems publishing a website to MobileMe.
Make sure you’re using the latest version of iWeb.
If you made changes to your site but you don’t see your changes online after you publish, try refreshing (reloading) the page in your web browser.
Make sure your MobileMe subscription is up-to-date by visiting www.me.com and signing in.
Try copying a file to your iDisk. If you can’t, you may need to resolve a problem with your MobileMe subscription before you can publish successfully.
Try publishing all your pages (not just changed pages) by choosing File > Publish Entire Site.
Try publishing your site to a folder. (In the Site Publishing Settings window, choose Local Folder from the “Publish to” pop-up menu.) If the site publishes, there might be a problem with your MobileMe service.
Make sure your Internet connection is working, and check to see whether you have any firewall, proxy servers, or other security programs open. If you do, try turning them off while you publish your site.
If everything seems to be in order, MobileMe may be having temporary problems. Wait several minutes and try again.