Problems with fast stone viewer

[jnsuffolk]

When I first installed this prog it worked fine. Then something happened. When I covert from raw to jpeg they become so overexposed you can hardly see the pic. I tried many different settings with no luck. Finally I deleted from my computer. I went into the registry and took out everything I could find for it. Reinstalled it and its alot better but still a tad bit on the light side. I'm using canon raw everything is up to date on camera and software. Any help would be great