Bought this scanner today. It installed fine under Vista. This scanner is replacing my old trusty HP 4C that is no longer supported under Vista (boo hiss!).
About 90% of my scanning is directly to PDF. When I tried this, the resulting scans were unusable, they were too light. Plus, the software would not remember the folder and file name that I wanted to use from the last scan, I had to Browse and re-enter it EVERY TIME. Huge pain. There is no way to adjust the brightness threshold using the automatic PDF buttons, it set the level automatically, which in my case was always too light, the scans were terrible and unusable. I had to use the general "Save" option, then drill into the settings EACH TIME and play with the threshold setting to get it right. Then deal with the saving location and name each time. This is not acceptable.
I have an HP G5040 at home that is MUCH better than this. This Canon is going back into the box and back to the store, I'll buy the same HP for my office. This is the first (and probably last) time I strayed from HP for peripherals, I learned my lesson.