Hello,
maybe this post could be useful http://answers.websitex5.com/post/3514
WebsiteX5 generates page without html errors or warnings by itself, but if you add custom code into your pages you must be aware of errors by yourself.
Generally there is a lot you can do in order to make your site seo friendly but this is regardless using websiteX5 , have a look at http://en.wikipedia.org/wiki/Search_engine_optimization

*** GOOGLE TRANSLATION ***

Hola,
tal vez esto último podría ser útil http://answers.websitex5.com/post/3514.
WebsiteX5 genera la página html, sin errores ni advertencias por sí mismo, pero si se agrega el código personalizado en sus páginas usted debe ser consciente de los errores de uno mismo.
En general, hay muchas cosas que puedes hacer para hacer que su sitio SEO friendly, pero esto es sin tener en cuenta con websiteX5, echar un vistazo ahttp://en.wikipedia.org/wiki/Search_engine_optimization

versión PHP: 5.3.10

Your server does not support this feature.

help

Hello Hugo,

in order to have WebsiteX5 working on your server you need to have php5 support, if it's not your case please try with an other one or ask them to add the support in your server, thank you