The latest versions of Mojarra (since 2.1.18 approx) log the following WARNINGS when running with ICEfaces. The logging is different depending on the mode that Mojarra is in. In Development, both the mime-type and missing resource WARNINGS are fired. In Production, just the mime-type WARNINGS are logged.

Development mode:

Apr 12, 2013 11:56:35 AM com.sun.faces.context.ExternalContextImpl getMimeType
WARNING: JSF1091: No mime type could be found for file TestScript. To resolve this, add a mime-type mapping to the applications web.xml.
Apr 12, 2013 11:56:35 AM com.sun.faces.application.resource.ResourceHandlerImpl logMissingResource
WARNING: JSF1064: Unable to find or serve resource, TestScript.
Apr 12, 2013 11:56:35 AM com.sun.faces.context.ExternalContextImpl getMimeType
WARNING: JSF1091: No mime type could be found for file CoreCSSOutput. To resolve this, add a mime-type mapping to the applications web.xml.
Apr 12, 2013 11:56:35 AM com.sun.faces.application.resource.ResourceHandlerImpl logMissingResource
WARNING: JSF1064: Unable to find or serve resource, CoreCSSOutput.

Production mode:

Apr 12, 2013 11:59:02 AM com.sun.faces.context.ExternalContextImpl getMimeType
WARNING: JSF1091: No mime type could be found for file TestScript. To resolve this, add a mime-type mapping to the applications web.xml.
Apr 12, 2013 11:59:02 AM com.sun.faces.context.ExternalContextImpl getMimeType
WARNING: JSF1091: No mime type could be found for file CoreCSSOutput. To resolve this, add a mime-type mapping to the applications web.xml.