diff -ur mysql-5.1.48.stock/sql/item_cmpfunc.cc mysql-5.1.48-bigint/sql/item_cmpfunc.cc
--- mysql-5.1.48.stock/sql/item_cmpfunc.cc	2010-06-03 23:50:02.000000000 +0800
+++ mysql-5.1.48-bigint/sql/item_cmpfunc.cc	2011-11-29 18:52:51.000000000 +0800
@@ -506,7 +506,8 @@
           !(field_item->is_datetime() &&
             args[1]->result_type() == STRING_RESULT))
       {
-        if (convert_constant_item(thd, field_item, &args[1]))
+        if ( (!(field_item->field->type() == MYSQL_TYPE_LONGLONG && args[1]->real_item()->type() == DECIMAL_ITEM))
+							    &&	convert_constant_item(thd, field_item, &args[1]))
         {
           cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
                            INT_RESULT);		// Works for all types.
@@ -522,7 +523,8 @@
           !(field_item->is_datetime() &&
             args[0]->result_type() == STRING_RESULT))
       {
-        if (convert_constant_item(thd, field_item, &args[0]))
+        if ( (!(field_item->field->type() == MYSQL_TYPE_LONGLONG && args[0]->real_item()->type() == DECIMAL_ITEM))  
+				                 &&  convert_constant_item(thd, field_item, &args[0]))
         {
           cmp.set_cmp_func(this, tmp_arg, tmp_arg+1,
                            INT_RESULT); // Works for all types.