Changes on Template dist/sommaire not visible

our website www.ifpindia.org contains css horizontal menu, it is work fine with firefox,IE6,IE7. In IE8, the css menu is not working. When IE-Compatibility button enable, it works fine. But I want change it into coding. so I want to embed the code

with the website Index file. I am new to SPIP, I read some document "http://programmer.spip.org/The-templates-aka-squelettes",
need to change the document in the squelettes-dist directory. In our server I found dist directory. I made changes to sommaire.html & sommaire_texte.html

There is no change on coding when I see in browser & If I see the view source the coding is not update.

Where will be the exact place of the template’s Index file for the change, need to activate.
I cleared Cache / server cache too.
help me to sort this issue.