I've got strong suspicions that I've got a similar bug to the one described on my machine and various anti-virus/anti spyware programs haven't been able to detect it - apparently there is a new wave of bugs which enter via "Java", which the anti-virus people haven't been able to get on top of yet - if you disable Java in the browser and just enable it for trusted sites, this prevents further nasties getting in -presumable the anti-virus/spyware people will get on the case soon, and just keep making sure to download updates regularly.