Hi Again
I've tried your suggestion of scanning with PCT AV. I did a full scan of my computer and came back with no infections found. I also tried clearing the cache in Firefox's settings. When I did this no alerts popped up from PC Tools.
I am the administrator for this PC and there are 3 other account users too. I clean all user's temp files etc in turn and then mine. To do this I use the portable version of CCleaner from my external hard drive.
I noticed on another user I got the same pop up alerts I did on mine when cleaning again tonight. Looking at Log Report on PCT I found another alert known as Trojan.VB.BFP. ( I probably didn't notice this first time around)
I've also added CCleaner to my allowed apps on PCT firewall. Not sure what to do next ..... mmmmm
Thanks for your quick reply to my post.