XMON background scanning

Hi!

On a MS Exchange Server 2003 SP2 (ver. 6.5, build 7638.2) I use
NOD32 for MS Exchange Server ver. 2.71.9.

Following the advice in "NOD32 Antivirus System - NOD32 Server Edition
for MS Exchange Server Installation" (nod_ug_exchange_en.pdf) I
disabled the background scanning in XMON so that it does not scan all
messages in the Exchange Information Store at each virus signature
database update. Also, I created a scheduled task of the
"XMON - Run background scan" type that runs daily outside working hours.

With these settings I noticed that the XMON background scanning option
gets back on after some time (it seems that happens after my XMON
background scanning task runs for the first time).
Is this a bug in NOD32?

Also, is there a way to get a log about running the XMON background
scanning tasks? I can't find any log about the tasks in either
NOD32 Control Center Event Log or NOD32 Scanner Logs.
In the XMON Setup I have enabled the following options:
Logs -> Content -> Scope: Detailed

TIA

-- rpr. /Robert Premuž/