diff -urN mysql-5.0.67-orig/sql/opt_range.cc mysql-5.0.67/sql/opt_range.cc
--- mysql-5.0.67-orig/sql/opt_range.cc	2008-12-18 18:57:05.000000000 -0800
+++ mysql-5.0.67/sql/opt_range.cc	2008-12-18 18:57:13.000000000 -0800
@@ -7752,6 +7752,7 @@
   uint cur_param_idx=MAX_KEY;
   key_map cur_used_key_parts;
   uint pk= param->table->s->primary_key;
+  uint last_valid_key_infix_len = 0;
 
   for (uint cur_index= 0 ; cur_index_info != cur_index_info_end ;
        cur_index_info++, cur_index++)
@@ -7916,6 +7917,11 @@
                                     last_part, thd, key_infix, &key_infix_len,
                                     &first_non_infix_part))
           goto next_index;
+
+
+        if (key_infix_len > 0) {
+           last_valid_key_infix_len= key_infix_len;
+        }
       }
       else if (min_max_arg_part &&
                (min_max_arg_part - first_non_group_part > 0))
@@ -8016,6 +8022,10 @@
                                       Field::itMBR : Field::itRAW))
     DBUG_RETURN(NULL);
 
+  if (key_infix_len == 0) {
+    key_infix_len= last_valid_key_infix_len;
+  }
+
   /* The query passes all tests, so construct a new TRP object. */
   read_plan= new (param->mem_root)
                  TRP_GROUP_MIN_MAX(have_min, have_max, min_max_arg_part,