I have an issue with Matrix package. When I try to load it (with R version 2.10.1 with Windows XP) I have an error message in return: Error in registerS3method(Info[i, 1], Info[i, 2], Info[i, 3], env) : aucun slot de nom "methods" pour cet objet de la classe "derivedDefaultMethod" any idea on how I could solve this issue ? thanks