Having some issues on one specific system so far. Was a fresh install of Windows XP SP3 with a clean install of NOD32 v4 Business. At startup ekrn.exe jumps to 45-50 percent CPU usage and would not back off unless you uncheck heuristics and just leave signatures and spyware/adware/riskware under the Threatsense engine parameter setup. I tried disabling and enabling things piece by piece and then enabling RTFS protection until I found it. Any reason why this should be happening? FYI, I uninstalled v4 at some point and went back to 3.0.684, same problem, same fix.