Windows hosts file and Norton (NIS 2008)

>
> Today I noticed that when I run NIS 2008 security inspector (when going
> on stage to check IP adresses) it just remove all entryes in hosts file
> in Windows/System 32/Drivers/etc
> However,when I run Spybot S&D it cretae new host file with over 8000
> entries but when I run Security inspector it's just delete all entries
> Is this normal?
> Checking my image file created with Acronis Home (which contains ONLY
> Windows Vista SP1 and no other software) I noticed that also hosts file
> is empty too.
> In both (image file and curent Windows Vista SP1) in hosts file (opened
> with notepad) entry is this:
>
> # COPYRIGHT (C) 1993-2006 MICROSOFT CORP.
> #
> # THIS IS A SAMPLE HOSTS FILE USED BY MICROSOFT TCP/IP FOR WINDOWS.
> #
> # THIS FILE CONTAINS THE MAPPINGS OF IP ADDRESSES TO HOST NAMES. EACH
> # ENTRY SHOULD BE KEPT ON AN INDIVIDUAL LINE. THE IP ADDRESS SHOULD
> # BE PLACED IN THE FIRST COLUMN FOLLOWED BY THE CORRESPONDING HOST
> NAME.
> # THE IP ADDRESS AND THE HOST NAME SHOULD BE SEPARATED BY AT LEAST ONE
> # SPACE.
> #
> # ADDITIONALLY, COMMENTS (SUCH AS THESE) MAY BE INSERTED ON INDIVIDUAL
> # LINES OR FOLLOWING THE MACHINE NAME DENOTED BY A '#' SYMBOL.
> #
> # FOR EXAMPLE:
> #
> # 102.54.94.97 RHINO.ACME.COM # SOURCE SERVER
> # 38.25.63.10 X.ACME.COM # X CLIENT HOST
>
> 127.0.0.1 LOCALHOST
> ::1 LOCALHOST
>
> Runed full system scan with NIS,Spybot and Kaspersky online scaner and
> nothig found
>
> I'm very confused,what's going on (or wrong)
>
> Vista SP1 32-bit NIS 2008 15.5
>
>
> --
> Lazaruslong