I thought 192.168.* addresses were for cable modem diagnostic pages. Can't be sure as I have a Terayon and it is not applicable.
Zone Alarm has been and is from time to time a known trouble maker. My advice is to dump it.
Here is a free PFW to replace it. I have used this for years with no problems.
http://www.kerio.com/dwn/kpf2-en-win.exe
If the problem persists try scanning with Counter Spy and/or Webroot Spysweeper. Spybot and Adaware just don't seem to do the business anymore.
HTH