Hi James, it looks like you are using the curving setting to set weights, which doesn't work that way. Curve to is meant to set a new top score for the assignment, but doesn't change the point value. E.g. if you give a 100 point assignment and then decide to ccurve it to 95 points, the students grades are recalculated to give them a % of the total curved points, but they still get the original point valude. So in the case above, a student who gets 95 points on a 100 point assignment, gets 100% of the total points for that assignment.
Grades are weighted by putting them into categories and setting weights on those categories. You need to go to the set categories tab, categorize your graded items, then go to set weights and weight each category with the value you like.