stuartbennett, because you said all the colors and formatting dissapeared, script settings were gone, etc, I very strongly suspect this had something todo with Plus! being unable to read your registry.
This could well have been a glitch (or even a setting
lol, the irony) in Vista itself. eg: like it prevented/blocked Plus! from reading the registry. Or your Windows account wasn't assigned the proper rights for apps to read the registry, etc...
Vista is very picky in those kind of things...