In admin console, the Message Count, Message Volumn and AS/AV chart stop showing the last 48hr charts. The 30day, 60days and 365days still showing though.

Got the following in zmlogswatch.out if I click the refresh button.
Code:
Tue Mar 15 23:10:54 2011: Spawned: 14056 -- Connected from 127.0.0.1:43000
Tue Mar 15 23:10:54 2011: Spawned: 14089 -- Connected from 127.0.0.1:43001
Tue Mar 15 23:10:55 2011: Spawned: 14104 -- Connected from 127.0.0.1:43002
Tue Mar 15 23:10:55 2011: Spawned: 14136 -- Connected from 127.0.0.1:43003
Use of uninitialized value $columns[1] in join or string at /opt/zimbra/libexec/zmrrdfetch line 165.
Use of uninitialized value $columns[1] in join or string at /opt/zimbra/libexec/zmrrdfetch line 165.
Use of uninitialized value $columns[1] in join or string at /opt/zimbra/libexec/zmrrdfetch line 165.
Use of uninitialized value $columns[1] in join or string at /opt/zimbra/libexec/zmrrdfetch line 165.
Tue Mar 15 23:11:11 2011: Spawned: 14204 -- Connected from 127.0.0.1:43005
Tue Mar 15 23:11:12 2011: Spawned: 14239 -- Connected from 127.0.0.1:43007
Tue Mar 15 23:11:12 2011: Spawned: 14240 -- Connected from 127.0.0.1:43008
Tue Mar 15 23:11:12 2011: Spawned: 14241 -- Connected from 127.0.0.1:43009
Tue Mar 15 23:11:12 2011: Spawned: 14248 -- Connected from 127.0.0.1:43010
Tue Mar 15 23:11:22 2011: Spawned: 14389 -- Connected from 127.0.0.1:43018
Tue Mar 15 23:11:22 2011: Spawned: 14406 -- Connected from 127.0.0.1:43019
Tue Mar 15 23:11:22 2011: Spawned: 14431 -- Connected from 127.0.0.1:43020
Tue Mar 15 23:11:23 2011: Spawned: 14450 -- Connected from 127.0.0.1:43021
Use of uninitialized value $columns[1] in join or string at /opt/zimbra/libexec/zmrrdfetch line 165.
Use of uninitialized value $columns[1] in join or string at /opt/zimbra/libexec/zmrrdfetch line 165.
Use of uninitialized value $columns[1] in join or string at /opt/zimbra/libexec/zmrrdfetch line 165.
Use of uninitialized value $columns[1] in join or string at /opt/zimbra/libexec/zmrrdfetch line 165.
Code:
$ zmcontrol status
Host
	antispam                Running
	antivirus               Running
	cbpolicyd               Running
	ldap                    Running
	logger                  Running
	mailbox                 Running
	mta                     Running
	spell                   Running
	stats                   Running
	zmconfigd               Running
Anyone has any idea?