DavidR,
I think what Stuck@home meant is that his Normal setting is acting the same in Vista as the High setting is acting on my XP.
Stuck@home,
As a last thought, could you set your Standard Shield on Low, then click on Customise, then select the Scanner(advanced) tab. The radio button in the Scan Created/Modified files should be on "Only Files with selected extensions" and not on "All files". (On High, this should be reversed). If this is not toggling correctly on your installation, or on Vista, then it would explain the problem.