Yes i mean SP and you say you have SP2 installed. Could be that the installer is not compatible with Vista SP2 and you need a patch to be applied for it to work. Best answer will come from them. It is their software so they should know how to get it working.
The only answer from the searches i got were to redownload the installer, which you said you did. Then to make sure the system was up to date.
I see the date on the installer is from last year. So it could be that it is not compatible with Vista SP2 at this point. Since that was just released.