Big value on bandwith after reenabled items

[fjrial]

Hi:

Graphs shows big values after zabbix was unable to get some values, disabled them, and them re-enabled them.

I have a problem with the graphs that display the bandwith of a network interface. The items of the graph are the counters of the router interface.

Today our firewall drops some packets from zabbix machine.. during that time, zabbix disabled the items. After that, zabbix reenabled the items.

But the graphic associated with the items shows a very high value on the first values, after reenabled. See screenshot attached.
this are the values associated with that moment (only for green line):
2010.Jun.02 11:28:50 666583104.2712
2010.Jun.02 11:27:51 787117113.3494
2010.Jun.02 11:26:28 1164612795.8222
2010.Jun.02 11:21:30 1324006728.6957
2010.Jun.02 11:16:00 800665198.8732
2010.Jun.02 11:14:49 765895902.2933
2010.Jun.02 11:13:34 771829857.1077
2010.Jun.02 11:12:29 774583628.3457
2010.Jun.02 11:11:08 756093614.5882

The items are snmpv2, update interval every 60 seconds, store value as delta

I know that those values are wrong because I have another monitoring tools, and none of them shows such high value.

thanks for any help.