This patch is from upstream:
http://websvn.kde.org/trunk/KDE/kdelibs/kinit/lnusertemp.c?view=markup

Except that I didn't use '#if 0' around mktemp().

--- ./kinit/lnusertemp.c.orig	2008-09-19 19:11:30.000000000 -0400
+++ ./kinit/lnusertemp.c	2008-09-19 19:13:28.000000000 -0400
@@ -178,7 +178,7 @@
      if (result == 0) return 0; /* Success */
      unlink(kde_tmp_dir);
      strncat(user_tmp_dir, "XXXXXX", PATH_MAX - strlen(user_tmp_dir));
-     mktemp(user_tmp_dir); /* We want a directory, not a file, so using mkstemp makes no sense and is wrong */
+     if (mkdtemp(user_tmp_dir)==0) return 1;
      return create_link(kde_tmp_dir, user_tmp_dir);
   }
   if ((result == -1) || (!S_ISLNK(stat_buf.st_mode)))
@@ -204,14 +204,14 @@
      if (result == 0) return 0; /* Success */
      unlink(kde_tmp_dir);
      strncat(user_tmp_dir, "XXXXXX", PATH_MAX - strlen(user_tmp_dir));
-     mktemp(user_tmp_dir); /* We want a directory, not a file, so using mkstemp makes no sense and is wrong */
+     if (mkdtemp(user_tmp_dir)==0) return 1;
      return create_link(kde_tmp_dir, user_tmp_dir);
   }
   result = check_tmp_dir(tmp_buf);
   if (result == 0) return 0; /* Success */
   unlink(kde_tmp_dir);
   strncat(user_tmp_dir, "XXXXXX", PATH_MAX - strlen(user_tmp_dir));
-  mktemp(user_tmp_dir); /* We want a directory, not a file, so using mkstemp makes no sense and is wrong */
+  if (mkdtemp(user_tmp_dir)==0) return 1;
   return create_link(kde_tmp_dir, user_tmp_dir);
 }