BleepingComputer.com: Symantic Email Proxy Pop-Up

I'm having problems with Symantic Email Proxy popups. I have run SEP and every online Virus scanner I can find. I have also run every dedicated virus removal tool I can find and several Anti-Spyware products. Nothing has been found. 'Hijack This' reveals nothing untoward.

This all started for me about one month ago. Having run the various scanners I tried System Restore and even a Ghost Image of some weeks previously, all to no avail. The 'Email Proxy' messages started again within 10 minutes.

My next move was to completely re-install Windows XP. Today the messages started again! I've been through all the scanners again as above with no detections. I've restored an Image of two days ago when everything was running OK. Again, the messages have started appearing at the rate of about ten per minute!

I have found several people with the same problem via Google, reporting it months or years ago in most cases, but nobody with a solution.

Please can someone help. I'm tearing out what little of my hair remains here!

Jose Crespo