diff -aruN a/CFXMLPreferencesDomain.c b/CFXMLPreferencesDomain.c
--- a/CFXMLPreferencesDomain.c	2009-02-19 08:32:54.000000000 -0800
+++ b/CFXMLPreferencesDomain.c	2012-04-25 10:35:53.000000000 -0700
@@ -239,9 +239,13 @@
 
 
 #if DEPLOYMENT_TARGET_MACOSX || DEPLOYMENT_TARGET_LINUX
+#include <grp.h>
 #include <stdio.h>
 #include <sys/fcntl.h>
 
+#define __kCFAdminGroupName       "admin"
+#define __kCFAdminFallbackGroupID 80
+
 /* __CFWriteBytesToFileWithAtomicity is a "safe save" facility. Write the bytes using the specified mode on the file to the provided URL. If the atomic flag is true, try to do it in a fashion that will enable a safe save.
  */
 static Boolean __CFWriteBytesToFileWithAtomicity(CFURLRef url, const void *bytes, int length, SInt32 mode, Boolean atomic) {
@@ -265,8 +270,10 @@
         } else {
             mode = 0664;
             if (writingFileAsRoot && (0 == strncmp(cpath, "/Library/Preferences", 20))) {
+                const struct group *grent;
                 owner = geteuid();
-                group = 80;
+                grent = getgrnam(__kCFAdminGroupName);
+                group = grent ? grent->gr_gid : __kCFAdminFallbackGroupID;
             }
         }
     }