I asked a related question the other day in the forums. What is the proper etiquette for replacing scans? Here's my personal procedure. As I go through a set, if I notice a poor or inaccurate scan I do the following steps:
1. Check out the other scans from the user in the set.
2. If the users scans are generally acceptable, I replace the scan without notifying admin. I did this recently with the scan of 1968 Topps football Bob Griese. The card in the original scan had an obvious crease. All the other scans from this user appeared ok and since the user that uploaded the original scan I replaced the card without trying to contact them. However, since I did not notify admin they kept the points.
3. If the users other scans are not acceptable, I make an attempt to contact the user, try and get opinion of other users through the fourm, and then contact admin to have the cards removed (I have not done this yet).
Although I do replace scans, I don't do it for the points. I only replace scans to make the site better. For point totals I only expect points from cards where I have uploaded the original scan.
I do have a scanning pet peeve though. I have come across users that have uploaded just the back/front of a parellel set without uploading a scan of the front/back that has the difference. (Topps collection for example). Its obvious that the user has the base set and is using the side of the card without the variation to get scan points. I know this is technically not wrong and it does add images to the database, but I do find it frustrating especially since cards without images are hard to come by for vintage collectors like myself.
My two-cents is worth slightly more than a penny.
-- Chad --