Incorrect time in mailbox.log file

[Kilath]

Hi,
in my mailbox.log file all the events are logged with a difference of 1 hour. For example, I can see from my mailbox.log a record like this one:

2011-09-13 15:23:17,557 INFO [LmtpServer-35] [ip=10.200.1.7;] lmtp - Delivering message: size=2383 bytes, nrcpts=1, sender=prvs=3237dbc6aa=xxx@xxxxxx.xxx, msgid=<01cc7220$Blat.v2.6.2$adb10222$2d8ccc994c6b@ xxxx.xx>

Instead from the web interface the user view the email with the correct time (in this example 2011-09-13 16:23:17)
audit.log has the same problem.

All other log files have correct time.

The timezone of the server is correctly setted (and I have tried what is explained here: [SOLVED] Zimbra.log has a different time zone than ubuntu mail server ).

The zimbra version is:
Release 5.0.18_GA_3011.UBUNTU8_64 UBUNTU8_64 FOSS edition
The OS version is:
Ubuntu x64 8.04

Thank you

[Kilath]

Is there someone who has experimented the same problem?
Thank you