i've already read the topics on stats that stop running after backup..
the only solution that seems to work is to write syslog via UDP, but on my case i got 99% of syslog cpu to do this work.
I've contacted zimbra support in italy (seacom), and they said me that the problem can be the filesystem. In my case, i've a SLES10 SP3 with reiserfs.
Before upgrade to 6.0.5, with a clean installation of 6.0.4 the stats work without problem (and any modification to syslog)
There is another solution to completly format filesystem and swap to ext3?