I also had some films developed, scanned and processed to CD, and the images were all grainy as well... I wasn't happy with them at all. The next time, I took my films to an ELKA photo lab and asked for the highest possible quality, and the images on CD were impeccable (at least for 200 ISO film; the 400 ISO film also came out a little grainy, but still better). My guess is also that your problem lies with the film processing lab... Take one film to another lab and ask for the highest possible quality on CD. Maybe you'll pay three or four times as much, but it can be worth it...

We do not see things as they are. ǝɹɐ ǝʍ sɐ sƃuıɥʇ ǝǝs ǝʍ