I am using Port Explorer 1.800 on WinXP Pro SP-1. I'm also using ZoneAlarm Pro 4.5 and KAV 5.0 (the technical preview). I have found that when KAV first launches, ZAP prompts as to whether or not to allow it (specifically, kavsvc.exe) to act as a server. However, Port Explorer does not list kavsvc.exe at all. I think that KAV is doing something funky, because Sysinternals Process Explorer can't resolve KAV's paths either (normally, it can provide the EXE's full path, and the command line it was started with). This does concern me, since I like to know everything that is going on with my system.