Florent,
> I'd sugest instead to use the ","

XSLT 1.0
     ^^^^

see the error message in the OP's posting

> javax.xml.transform.TransformerConfigurationException: Could not  
> compile stylesheet
>         at  
> com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl.ne 
                     ^^^^^

David