Exception in stats thread: mailboxd.csv

[maumar]

This is: Release 6.0.6_GA_2330.RHEL5_20100505191632 CentOS5 NETWORK edition.

i note this error in mailbox.log after upgraded to 6.0.6

2010-07-07 00:00:07,451 INFO  [btpool0-249://localhost:7071/service/admin/soap/BackupRequest] [name=zimbra;ip=127.0.0.1;] backup - Backup request finished
2010-07-07 00:00:10,572 WARN  [mailboxd.csv] [] perf - Exception in stats thread: mailboxd.csv
java.io.FileNotFoundException: /opt/zimbra/zmstat/2010-07-03/mailboxd.csv.gz (Permission denied)
        at java.io.FileOutputStream.open(Native Method)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:179)
        at java.io.FileOutputStream.<init>(FileOutputStream.java:131)
        at com.zimbra.common.util.FileUtil.compress(FileUtil.java:69)
        at com.zimbra.common.stats.StatsDumper.rollover(StatsDumper.java:101)
        at com.zimbra.common.stats.StatsDumper.call(StatsDumper.java:129)
        at com.zimbra.common.stats.StatsDumper$1.run(StatsDumper.java:79)
        at java.lang.Thread.run(Thread.java:619)

they are many:

 grep denied mailbox.log|grep csv|wc -l
2360

apart from do

chown -R zimbra:zimbra /opt/zimbra/zmstat

what should I do to avoid this issue next days?