1548-Cannot load from mysql.proc. The table is probably corrupted
http://bugs.mysql.com/bug.php?id=50183
原因是mysql.proc升级时有个字段没有升级成功。
在5.1中mysql.proc表的comment字段是varchar(64)：
`comment` char(64) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL DEFAULT '',
但在5.5中应该是text：
`comment` text CHARACTER SET utf8 COLLATE utf8_bin NOT NULL, So，执行下面的语句，把这个字段修改为text，就彻底OK了：
ALTER TABLE `proc` MODIFY COLUMN `comment` text CHARACTER SET utf8 COLLATE utf8_bin NOT NULL AFTER `sql_mode`;
