I have successfully generated W3C compliant pages in the past from SitePublisher. For this, you have to code all of of your components, page templates (including page level XSL), etc. in accordance with whatever you are trying to go after (whether it is XHTML or HTML or Strict or Transitional). It is not something that happens auto-magically by switching different page types.
Could you please elaborate on this.
When using SitePublisher, the HTML that is sent to the browser is "assembled" from two primary sources: 1.) Page XSL and 2.) Component XSL (or directly Component HTML).In order to make sure that your entire page is W3C compliant, you have to make sure that any / all of your components as well as the page level XSL conforms to W3C standards.In order to get anywhere, you'll first need to know what is a component and page level XSL. Have you worked with that before?HTH!
What version of LS are you using? What errors are you seeing that are not validating against W3C standards?You probably need to hire somebody who knows how to do this. IMHO, this is not something that would be easily done over the forums. Also it is a bit tedious and time-consuming activity -- not sure if someone is willing to do that for you over the forums :-)!