To be safe and after getting 5 of these in quick succession yesterday afternoon I went off line completely. Ran virus and spyware checks and it seems my PC is secure enough. Then went back on line and visited several other sites and got no sign of the virus warning, which btw seems to be an attempt to make us sign up for some antivirus system or other. Anyway no sign of it anywhere else but on attempted return to the VP yesterday I could not get past the same bug. Gave up and this morning am using my lapbook that runs on Linux as Linux is considered pretty safe against virus attacks (Cue someone who will tell me it isn't).
I await BMs report on what it is and where it is coming from before going back to the PC and Vista. Meanwhile am squinting hard to read a 7 inch screen which, whilst adequate for the purpose for which it was originally purchased, is not pleasant for continued use.