Thank you to everyone who has responded and tried to help with this. I have now, after much hair-pulling and emails to Microsoft and Kaspersky got to the bottom of the issue.
Kaspersky’s Internet Security 2010 ’Anti-Banner’ (new to this edition, and just this week had a new set of rules added by Kaspersky in a daily update) is embedded within every browser located in the system - and exclusively to Vista, it seems it is not de-activated when the program is switched off - it behaves in more of a ’stand alone’ capacity - and so when I shut down Kaspersky to rule that out of the problem, nothing changed!!
So armed with this info, I added my url to the ’trusted urls within it’s own section (not universal, every feature needs to be told it seems!) and problem sorted!.
I am very grateful for all the help, and I am very relieved to not have to find another CMS to use instead!.
Cheers.