Part of the installation I had to install Network Monitor 3.1, so I would be able to sniff on the HTTP.
After few days and one restart I came to a situation that the System service was taking almost 100% CPU which my laptop to NOT FUNCTION!
I download and ran process explorer and saw that at least 50% CPU is taken on "NDIS.SYS!TrFilterDprIndicateReceiveComplete+0x3efe" --> Network.
I immediately suspected NM 3.1 and removed it from system (after few hours that system was unstable) and that resolved the issue.
Suggestion DO NOT INSTALL NM 3.1 on VISTA with Intel 3945ABG card (apparently there is an updated driver but I haven't checked it yet)