diff -up sblim-sfcb-1.3.10/cmpimacs.h.orig sblim-sfcb-1.3.10/cmpimacs.h
--- sblim-sfcb-1.3.10/cmpimacs.h.orig	2010-12-06 14:24:21.599940670 +0100
+++ sblim-sfcb-1.3.10/cmpimacs.h	2010-12-06 14:32:05.792322703 +0100
@@ -1263,7 +1263,7 @@ inline static CMPICount CMGetArgCount (c
 
     // CMPIString Macros
 
-#   define CMGetCharPtr(s)                                 ((char*)s->hdl)
+#   define CMGetCharPtr(s)                  ((s) ? (char*)(s)->hdl : NULL)
 
 #   ifdef CMPI_INLINE
        /** Get a pointer to a C char* representation of this String.