css tomcat configuration JSF Problem

i have tomcat-7 with only 1 application inside. the application is a simple jsf webpage. when i start a [login to view URL] file inside webapps folder everything is fine. BUT when i start tomcat, something overwrites some of my css or something cannot be loaded. i need someone to fix this. we cannot make any changes to the application lib folder or to the tomcat lib folder. because with a fresh tomcat-7 the site works fine. so it must have something to do with the tomcat configuration. pls send pm for full tomcat download URL