还是一个cacti错误日志的问题

这个问题已经困扰我很久了，截取了部分日志如下，这些都是红色的错误日志，提示好像是mysql中不能插入重复的条目，我手动登陆到mysql上，在cacti库中，执行
INSERT INTO poller_output (local_data_id, rrd_name, time, output) VALUES (172,'mem_swap','2011-01-20 11:05:09','3785536'),(173,'users','2011-01-20 11:05:09','2'),(174,'proc','2011-01-20 11:05:09','302'),(177,'mem_buffers','2011-01-20 11:05:09','28296'),(178,'mem_swap','2011-01-20 11:05:09','3785536'),(179,'users','2011-01-20 11:05:09','2'),(180,'proc','2011-01-20 11:05:09','281'),(183,'mem_buffers','2011-01-20 11:05:09','27404'),(184,'mem_swap','2011-01-20 11:05:09','3785536'),(185,'users','2011-01-20 11:05:09','2'),(186,'proc','2011-01-20 11:05:09','279')
这个是可以成功执行的，但是接着执行下面的第二条的时候就不能执行了，就像日志中的一样，也是1062错误。我想也是，poller_output的表结构是这样的:,当然不能插入重复的记录，
mysql> desc poller_output;
+---------------+-----------------------+------+-----+---------------------+-------+
| Field         | Type                  | Null | Key | Default             | Extra |
+---------------+-----------------------+------+-----+---------------------+-------+
| local_data_id | mediumint( unsigned | NO   | PRI | 0                   |       |
| rrd_name      | varchar(19)           | NO   | PRI |                     |       |
| time          | datetime              | NO   | PRI | 0000-00-00 00:00:00 |       |
| output        | text                  | NO   |     | NULL                |       |
+---------------+-----------------------+------+-----+---------------------+-------+
4 rows in set (0.02 sec)

现在的问题是，为什么cacti会产生多条这样的插入记录呢？我仅仅是执行了一次Rebuild Poller Cache。而且不知道为什么，我加入的cacti插件都不生效了，界面上显示不出来，而之前是好的。
下面的是cacti产生的一些日志

01/20/2011 11:05:12 AM - SPINE: Poller[0] ERROR: SQL Failed! Error:'1062', Message:'Duplicate entry '172-mem_swap-2011-01-20 11:05:09' for key 1', SQL Fragment:'INSERT INTO poller_output (local_data_id, rrd_name, time, output) VALUES (172,'mem_swap','2011-01-20 11:05:09','3785536'),(173,'users','2011-01-20 11:05:09','2'),(174,'proc','2011-01-20 11:05:09','302'),(177,'mem_buffers','2011-01-20 11:05:09','28296'),(178,'mem_swap','2011-01-20 11:05:09','3785536'),(179,'users','2011-01-20 11:05:09','2'),(180,'proc','2011-01-20 11:05:09','281'),(183,'mem_buffers','2011-01-20 11:05:09','27404'),(184,'mem_swap','2011-01-20 11:05:09','3785536'),(185,'users','2011-01-20 11:05:09','2'),(186,'proc','2011-01-20 11:05:09','279')'

01/20/2011 11:05:12 AM - SPINE: Poller[0] ERROR: SQL Failed! Error:'1062', Message:'Duplicate entry '172-mem_swap-2011-01-20 11:05:09' for key 1', SQL Fragment:'INSERT INTO poller_output (local_data_id, rrd_name, time, output) VALUES (172,'mem_swap','2011-01-20 11:05:09','3785536'),(173,'users','2011-01-20 11:05:09','2'),(174,'proc','2011-01-20 11:05:09','302'),(177,'mem_buffers','2011-01-20 11:05:09','28708'),(178,'mem_swap','2011-01-20 11:05:09','3785536'),(179,'users','2011-01-20 11:05:09','2'),(180,'proc','2011-01-20 11:05:09','278'),(183,'mem_buffers','2011-01-20 11:05:09','27552'),(184,'mem_swap','2011-01-20 11:05:09','3785536'),(185,'users','2011-01-20 11:05:09','2'),(186,'proc','2011-01-20 11:05:09','280')'

没去 cacti 论坛问问啊?